Bernina 770 Service And Maintenance Manual
  1. Manuals
  2. Brands
  3. Bernina Manuals
  4. Sewing Machine
  5. 770
  6. Service and maintenance manual
Bernina 770 Service And Maintenance Manual

Bernina 770 Service And Maintenance Manual

Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
Service- and Maintenance Manual
BERNINA 790
BERNINA 770
BERNINA 740
BERNINA 720
BERNINA International AG
Seestrasse 161
CH-8266 Steckborn
Switzerland
Seite 1 von 178

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the 770 and is the answer not in the manual?

Questions and answers

Related Manuals for Bernina 770

Summary of Contents for Bernina 770

  • Page 1 Service- and Maintenance Manual BERNINA 790 BERNINA 770 BERNINA 740 BERNINA 720 BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 1 von 178...

  • Page 2: Table Of Contents

    1.5 Handling Adjustments ........................... 12 1.6 Abbreviations / Names used ......................... 12 1.7 Cleaning ..............................13 1.8 Technical Details of the New 7 Series ....................14 Chapter 2 – Electronics and Wiring................15 2.1 PCBA-Base – General Information ....................15 2.1.1 PCBA-Base (B790, B770, B740, B720) ..................
  • Page 3 3.2.17 PCBA-Dual Feed Sensor ......................48 3.2.18 PCBA-Accessories-Interface ....................... 48 3.2.19 Embroidery Module Interface (BERNINA 780 and 750) .............. 49 3.2.20 PCBA-Lower-Thread-Sensor ....................... 50 3.3 Mechanical Components ........................51 3.3.1 Hook and Hook Driver ........................51 3.3.2 Stitch Plate Support with Integrated Thread Cutter Unit ..............54 3.3.2.1 Blade Change on Mounted Thread Cutter Unit ................
  • Page 4 1b Machine Soft- and Firmware Data ....................116 1c Machine Operating Time Data ......................117 1d Machine Stitch Counter Data ......................117 1e BSR (BERNINA Stitch Regulator) Data ................... 117 1f Machine Servicing Data ........................118 1g Saving / Loading Customer Data ..................... 119 1h Customer Data ..........................
  • Page 5 8.5.1 Measures to be taken before the Maintenance ................175 8.5.2 Measures to be taken after the Service ..................175 8.5.3 Functional Check ......................... 176 8.5.4 Maintenance Checklist BERNINA 790 / 770 / 710 / 720 ............. 177 8.5.5 Embroidery Module ........................178 Document Revision History ..................178...

  • Page 6: Chapter 1 - General Information

    This service manual is only available in electronic format. It can be downloaded from BERNINA Infogate at http://infogate.bernina.com under 'Service Manual' in the 'Tech. Service' register. If you don't have access to Infogate, contact your local BERNINA importer. They'll be glad to be of assistance.

  • Page 7: Warning: Dangerous Voltage Levels

    The capacitors require 30 seconds to discharge after the power supply has been switched off. We recommend waiting for the complete discharging of the capacitors before starting any servicing work on the PCBs. Caution! High voltage BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 7 von 178...

  • Page 8: Esd-Related Note: Electrostatic Discharge (Esd)

    4. Only use conductive ESD-capable plastic/foil pouches and ESD transport boxes for dispatching electronic components – even if the components might be faulty. Electrostaticdischarge_ESD 5. To prevent consequential damage or harm, treat faulty PCBs in the same manner as new ones. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland...

  • Page 9: Tools And Gauges

    Vernier caliper, multimeter, TORX screwdriver no. 6, 8, 10 and 10 with 200mm blade length; 15, 20 and 20 with 200mm blade length, 25, and angular TORX nos. 6 and 10, 10mm ring wrench, 6mm flat wrench. Special Tool set for 7 Series Art.-No.: 034384.71.07 Spezialwerkzeug Set 7er Serie Trousse à...
  • Page 10 Common Tool Set for 7 Series Art.-No.: 034383.70.00 Allgemeines Werkzeug Set 7er Serie Trousse à outils généralement pour la Série 7 Name Application Picture Art.-No. Bezeichnung Verwendung Bild Application Image Adjusting needles Needle and hook adjustment 338109.03.3+ Einstellnadeln 130/705 H TCN 80 Nadel- und Greifereinstellung Réglage de l’aiguille et du crochet...
  • Page 11 Ø1.5, 2.3, 3.2) (Size 3.2) Helpful Tools for BERNINA Sewing and Embroidery Systems Hilfreiche Werkzeuge für BERNINA Näh- und Sticksysteme Trousse à outils secourable pour les maschine à coudre informatisée de BERNINA Spring balance gauge Tension of thread regulator spring 006038.50.00...

  • Page 12: Handling Adjustments

    Throughout the whole manual the following abbreviations have been used. We have reserved the right not to explain individual abbreviations within the text. Abbreviation: Stands for: BERNINA Dual Feed BERNINA Stitch Regulator Direct Current EEPROM Electronically Erasable Programable Read Only Memory...

  • Page 13: Cleaning

    Toothed belt drive and motor pulley. • Hook drive mechanism. • Dual and sideways motion feed transmission. Area of electronics: • All sensors / light barriers / switches / electronic group of parts. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 13 von 178...

  • Page 14: Technical Details Of The New 7 Series

    1.8 Technical Details of the New 7 Series Features BERNINA 790 BERNINA 770 BERNINA 740 BERNINA 720 Technical Line voltage 100 - 240 Volt 100 - 240 Volt 100 - 240 Volt 100 - 240 Volt 50-60 Hz 50-60 Hz...

  • Page 15: Chapter 2 - Electronics And Wiring

    PCBA-front-cover, right X-2111 black sideways-motion motor white PCBA-module X-42 blue stitch-length motor X-24 white PCBA-detection X-42 X-15 white embroidery module X-40 black PCBA-lower-thread sensor X-24 X-15 EEPROM X-40 BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 15 von 178...

  • Page 16: Pcba-Cpu-Module (Arm9) - General Information

    CPU-module from the 'old' PCBA and add to the • Data new. Connectors: • According to picture B790, B770, B740, B720 2.2.1 PCBA-CPU-Module / ARM9 ( X-1 PCBA-Base X-28 TFT screen Contacts of PCBA-Base BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 16 von 178...

  • Page 17: Pcba

    Seam securing (S-2) Pattern end (S-3) Pattern begin (S-4) only 780 • Connecting PCBA left front cover with PCBA-RET and PCBA right front cover. PCBA-RET connector Sewing speed slide potentiometer BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 17 von 178...

  • Page 18: Pcba Right Front Cover (B790, B770, B740, B720)

    (S-3) and right needle Key-function foil position (S-4). PCBA-Base • Supply for LCD backlighting connector • Supply for LED freearm lighting Touch screen connector LCD backlighting connector BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 18 von 178...

  • Page 19: Pcba-Power (B790, B770, B740, B720)

    The cause must be identified and removed. Only a replacement fuse of the correct rating must be used. It is essential to test the functions on replacing the fuse. BERNINA International AG Seestrasse 161...

  • Page 20: Pcba-Threader (B790, B770, B740, B720)

    Light barrier 2 receives the AB signal of the increment disc. This signal is used for the motor control, among others. • The hook track signal (light barrier 3). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 20 von 178...

  • Page 21: Pcba-Ret (B790, B770, B740, B720)

    2.13 PCBA Feed-Dog Drop Detection (B790, B770, B740, B720) The PCBA-detection contains: • Light barrier • Connector Connector: • According to picture Task: • Reporting feed-dog status (up/lowered) to CPU via PCBA-base BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 21 von 178...

  • Page 22: Pcba-Lower-Thread Observer (B790, B770,B720)

    The upper and lower position of the presser foot bar is recognized via light barriers and the presser foot pressure via the hall sensor and the magnetic strip. Light barrier Hall sensor BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 22 von 178...

  • Page 23: Sensor Support Abc (Presser Foot Recognition) (B790, B770, B740, 720)

    Infrared (IR) LED's • Photo transistors X-38 PCBA- Base via Connector: harness • According to picture Task: • Recognition of presser feet and buttonhole foot signal via sensors. Sensors BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 23 von 178...

  • Page 24: Cable Harness

    6 Accessories connector white X 38 / / PCBA-Base 7 Dual Feed sensor white X 38 / / PCBA-Base 8 ABC sensor support white X 38 / / PCBA-Base BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 24 von 178...

  • Page 25: Bernina 790 Block Diagram (B770, B740, B720)

    2.19 BERNINA 790 Block Diagram (B770, B740, B720) BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 25 von 178...

  • Page 26: Handling Of Electronic Components

    Electronic components that have been manipulated or repaired by oneself are excluded from the repair/replacement process. They will be disposed of. BERNINA International AG reserves the right to charge the original price (of the new component) for electronic components that have been manipulated, repaired by oneself or improperly packaged.

  • Page 27: Chapter 3 - Removal And Refitting Of Components

    • Press cover down into the locks. • Refit the 4 screws a (T20 M4x16). • Refit screw b (T20 M4x66). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland...

  • Page 28: Front Cover

    • Rehook front cover at top, taking care not to pinch any cables in the duct. • Insert cover bottom into base plate, ensuring that the belt cover latches sit properly. • Refit and retighten screws c. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 28 von 178...

  • Page 29: Free Arm Cover

    (see 3.2.20). • Refit and retighten 2 screws b (T15). • Retighten screw a (T10 M4x8). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 29 von 178...

  • Page 30: Free Arm Cover Plate

    • Refit and retighten screw b. • Refit the cover and bobbin door. Warning! Take care not to interfere with the lower-thread sensor wires to avoid damaging them. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 30 von 178...

  • Page 31: Base-Plate Cover

    Warning! Take care not to interfere with the lower-thread sensor wires to avoid damaging themalso ensure the embroidery connection cable is correctly positioned before refitting base plate cover. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 31 von 178...

  • Page 32: Belt Cover

    • Secure belt cover with 2 screws a (T10) on fixing plate. • Tilt sewing machine to refit fastening screw b (T20) on base plate underside. • Refit handwheel 1 onto main shaft. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 32 von 178...

  • Page 33: Electronics And Sensors

    PCBA-Cover ribbon cable properly. • Replug PCBA-RET/front left PCBA-Cover properly. • Refit button (marked with a yellow arrow in the upper picture). • Refit the covers (see 3.1). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 33 von 178...

  • Page 34: Stitch-Length And Stitch-Width Adjusting Knobs

    • Rewind the winder wires around the wire harness 2. Then reconnect the PCBA-Base plug 1 (see 4.13). • Refit covers (see 3.1). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 34 von 178...

  • Page 35: Winder Motor

    • Remove complete winder unit (see 3.2.3). Note: Replace entirely if necessary. Assembly: • Refit complete winder unit (see 3.2.3). • Functional check (see 4.13). • Refit covers (see 3.1). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 35 von 178...

  • Page 36: Lc Display / Touchscreen

    • Stick self-adhesive copper foil tape over the severed copper foil to bridge the cut. • Refit front right and front left PCBA-Cover to front cover (see 3.2.1). • Refit the covers (see 3.1). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 36 von 178...

  • Page 37: Pcba-Ret / Rubber Key Pad / Ribbon Cable

    • Reposition PCBA-RET c and bridge b properly and slightly tighten 4 fastening screws 1 (T9). • Reconnect PCBA-RET ribbon cable a to front left PCBA- Cover. • Refit the covers (see 3.1). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 37 von 178...

  • Page 38: Pcba-Base

    • Reconnect all plugs (note the color coding, see next page). Note: Ensure that no wires are within the FHS light barrier area 3. Important! Is the EEPROM attached? BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 38 von 178...
  • Page 39 PCBA-lower-thread sensor X-103 black wireless module * For connector details see 2.18 cable harness X-1701 X-1503 X-1700 1702 X-17 X-3112 X-38 X-3111 X-30 X-2111 X-42 X-24 X-15 EEPROM X-40 BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 39 von 178...

  • Page 40: Pcba-Cpu-Module

    The current state of the firmware must be checked after assembly of the new PCBA-CPU- module. If it is not the latest version, the firmware must be updated (via updating procedure). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 40 von 178...

  • Page 41: Eeprom (Electrically Erasable Programmable Read-Only Memory)

    • Attach EEPROM 2 to base. • Take care to fit EEPROM in the correct position (markings must match) and avoid bending the contacts. EEPROM fitting position Markings must match. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 41 von 178...

  • Page 42: Freearm Led Sewing Light

    3.1). Risk of short circuit: To avoid risk of a short circuit, stick a strip of electrical insolation tape to the bottom of the frame arm of the machine. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 42 von 178...

  • Page 43: Pcba-Power Including Pcba Housing

    • Refit PCBA cover 1, PCBA housing and air duct, taking care not to interfere with the main switch and power plug. • Refit the covers (see 3.1). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 43 von 178...

  • Page 44: Pcba-Power

    Insert ESD protective gasket into slot. • Tighten the 3 fastening screws a (T10) to secure PCBA-Power in the housing. • Refit PCBA-Power and housing (see 3.2.11). • Refit the covers (see 3.1). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 44 von 178...

  • Page 45: Head Frame Led Sewing Light

    • Fit the left LED sewing light into the socket and use small screwdriver (T10) 030475.50.00 to tighten the fastening screw 1. • Refit the covers (see 3.1). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 45 von 178...

  • Page 46: Presser-Foot Height Sensor

    • Reconnect plug 1. • Refit covers. Note: BERNINA model 710 has no magnet strip and Hall sensor. With the 710 the presser-foot height sensor 4 must positioned exactly in the centre of the rear actuating lug and secured with screw 3.

  • Page 47: Pcba-Threader

    • Refit covers. Caution: Risk of Breakage! Take care that sensor support 2 doesn't catch edges while fitting it. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 47 von 178...

  • Page 48: Pcba-Dual Feed Sensor

    • Remove 2 screws a (T10 M3x6). Tip: For access to screws see film. • Remove PCBA-Accessories-Interface 1. • Disconnect plug 2. Assembly: • Lower dual feed. • Position PCBA-Accessories-Interface 1. • Retighten 2 screws a. • Refit covers. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 48 von 178...

  • Page 49: Embroidery Module Interface (Bernina 780 And 750)

    3.2.19 Embroidery Module Interface (BERNINA 780 and 750) Disassembly: • Remove base plate cover (see 3.1.6). • Remove PCBA-EMB connector. • Remove the two collar screws (T8) using the angled torx. • Disconnect PCBA-EMB plug. • Remove insulation foil. Assembly: •...

  • Page 50: Pcba-Lower-Thread-Sensor

    (fig. 1). • Insert guiding pin on the left of the lower-thread sensor into guiding rail (red circle, fig. 1). • Close the bobbin door. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 50 von 178...

  • Page 51: Mechanical Components

    Hook race ring movement is locked for all other directions. • Insert the setting hook including gauge shaft 734591.70.00 and fitted pressure spring into hook race ring. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland...
  • Page 52 (give some pressure on the hook drive belt). • Refit and adjust belt tensioner. ~ 4.5mm BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 52 von 178...
  • Page 53 Replace hook if it is badly scratched or has broken hook tip. • For lubrication of hook refer to lubrication diagram (chapter BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 53 von 178...

  • Page 54: Stitch Plate Support With Integrated Thread Cutter Unit

    • When servicing the machine, the thread cutter must always be removed for cleaning purposes. • The blade is a wear part and therefore available as an individual part. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 54 von 178...

  • Page 55: Blade Change On Mounted Thread Cutter Unit

    Warning! Do not touch blade of knife – risk of injury! Disassembly: • Start BERNINA sewing and embroidery computer in Service Program, select test 6e. Then remove needle, presser foot and stitch plate. • Press thread cutter button on head frame. Then press the green box in the window that appears in the display to confirm.
  • Page 56 Note: Remove fabric remnant and inserted sewing needle. • Close bobbin door. Then complete test 6e. Refit stitch plate, attach presser foot and insert new needle. Then testrun machine and thread cutter. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 56 von 178...

  • Page 57: Thread-Tension Unit

    • Remove the 2 fastening screws (2x T20, picture 3). • Carefully remove the whole upper-thread tension unit from the rubber cushion, taking care not to remove the rubber cushion from its bore (picture 4). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 57 von 178...
  • Page 58 Reposition the 4 clips (032341.70.00) to their correct places and press to fix them. • When done, refit all covers. • Adjusting will be done via the Service Program (see 6j). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 58 von 178...

  • Page 59: Mechanical Basic Setting Of The Thread Tension

    Recheck the distance. Correct if required. • Retighten upper screw of thread take- up lever cover. • When done, refit covers. • Adjusting will be done via the Service Program (see 6j). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 59 von 178...
  • Page 60 Note: The side measured with “9.95”mm of the distance gauge 735386.50.00 must go up and down very easy over the tension spring. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 60 von 178...

  • Page 61: Clutch Carriage

    • Relay pull solenoid wire properly. Replug connector a and refit bracket 3. • Refit connecting strap between clutch carriage and thread-cutter release lever and screws 2 (2 x T10). • Use 3.0mm pin a 007937.50.00 to pin thread catcher. BERNINA International AG Seestrasse 161 CH-8266 Steckborn...
  • Page 62 • Check and adjust base shaft synchronization (see 4.5.1) • Functional check of solenoid (see Service Program Note: Service Information no. 47286 gives details regarding setting of solenoid for thread cutting and stitching start. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 62 von 178...

  • Page 63: Threader Head

    • Push threader head onto threader bar in correct position. • Release needle threader holder. • Insert needle. • Functional check • Adjust threader if necessary (see 4.9). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 63 von 178...

  • Page 64: Needle Bar Support

    7. • Slide needle bar support 12 to front, then to the left and out of thread take-up crank. • Remove seating 13 that sits behind needle bar support. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 64 von 178...
  • Page 65 • Refit zigzag support with screw f and spring 8. • Rehook spring 8. • Remove pinning tool 14. • Adjust needle distribution (see 4.4.2). • Refit covers. build-in BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 65 von 178...

  • Page 66: Needle Bar

    • Rough-set the needle bar guide and secure the setscrew b (T6 M3x4). • Rehook spring 1. • Refit needle bar support (see 3.3.7). • Adjust threader (see 4.9). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 66 von 178...

  • Page 67: Needle Clamp

    • Use feeler gauge 8 to press spring 3 down, then slide needle clamp 5 over needle bar 7 in direction of arrow as indicated. • Retighten needle height screw b. • Refit needle clamp screw a. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland...

  • Page 68: Threader Mechanism

    • Reposition dowel 8 so that pressure spring sit’s in the groove of the dowel (see picture a). • Rehook tension spring 10. • Rehook tension spring 9. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 68 von 178...

  • Page 69: Main Motor

    • Position motor back into motor bracket. • Retighten screw a including u-washer and serrated washer. • Refit drive belt and ventilation fan. • Adjust belt tension (see 4.1.2). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 69 von 178...

  • Page 70: Dual Feed

    • Refit PCBA-Dual-feed 2 and PCBA-Accessories-connector 3. • Reconnect all plugs, lay cable in duct and close. • Refit right LED housing. • Adjust dual feed in X-direction (see 4.6.2). • Refit covers. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 70 von 178...

  • Page 71: Thread Take-Up

    • Refit link shaft 4 with bushing support and screw a. • Retighten setscrew b on the flat of crank 5 so that there is no play or clamping. • Refit needle bar support, thread tension unit and covers. BERNINA International AG Seestrasse 161 CH-8266 Steckborn...

  • Page 72: Restraint Guided Feed Advance Link Lever

    • Loosen screw 9 (T8) of bearing pin, then remove bearing pin. • Pull lift-/advance 16 link out, lifting it away from you and taking care not to lose the pressure spring. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 72 von 178...
  • Page 73 734562.50.00. • Refit circlip 8. • Turn handwheel and check for ease of running. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 73 von 178...

  • Page 74: Stitch-Length Crankshaft

    • Slightly push small belt pulley and white plastic washer against circlip and retighten setscrew b (T8). • Adjust mechanical basic setting (balance) of feed-dog (see 4.6.3 service program • Refit the covers (see 3.1). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 74 von 178...

  • Page 75: Base Shaft

    • Use 3.0mm pinning tool 007937.5.00 to pin base shaft against lift cam. • Slide drive belt over belt pulley. Check belt tension (see 4.1.1). • Check loop lift (see 4.5.3). Check position and timing of knife cam. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 75 von 178...

  • Page 76: Stitch-Length Stepping Motor

    • Place 0.3mm feeler gauge 9 under stop 7 of drive gear pinion 6. • Set stop 7 of drive gear pinion 6 against rubber buffer 8 and retighten setscrew b. • Remove feeler gauge 9. • Refit stepping motor. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 76 von 178...

  • Page 77: Sideways-Motion Stepping Motor (B780)

    • Main feed-dog: Adjust position within stitch plate in X direction (see 4.6.1) • Refit air duct. • Refit freearm cover plate (see 3.1.5). • Refit freearm cover (see 3.1.4). • Refit rear cover (see 3.1.2). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 77 von 178...

  • Page 78: Presser-Foot Pressure Stepping Motor

    • Replug stepping motor connector. • Replug PCBA-Threader connector. • Run Test 6h in Service Program. • Refit rear cover (see 3.1.2). • Refit head cover (see 3.1.1). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 78 von 178...

  • Page 79: Stitch-Width Stepping Motor

    8. • Retighten setscrew c. • Complete test • Remove pinning tool 6 and feeler gauge 7. • Adjust needle distribution (see 4.4.2). • Refit covers. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 79 von 178...

  • Page 80: Presser-Foot Pressure - Toothed Rack Bearing

    • Position entire toothed rack bearing at rear head plate and retighten three screws a. • Slide pinion 5 over shaft. • Refit wheel 3 including washer and circlip 4. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 80 von 178...

  • Page 81: Chapter 4 - Settings

    For servicing, we recommend that you always use the accessories included with the machine or purchased specifically for it. These are the following: power cable, foot control, buttonhole foot, embroidery module and hoop, BSR foot, and other accessories. BERNINA International AG Seestrasse 161 CH-8266 Steckborn...

  • Page 82: Belt Tensions

    • Untigthen screw b (T20), then use adjusting spanner # 733019.70.00 to turn the bearing until the specified tension value has been reached. • Retighten screw b. Note: Clockwise turning: belt tension tightens. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 82 von 178...

  • Page 83: Drive Motor

    • Turn screw a (T20) to set the clearance to 18.0mm. o Clockwise turning gap closes. 4.2.1 o Counterclockwise turning gap opens. Note: Disconnect PCBA-Threader Sensor to 18mm clear access to the screw. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 83 von 178...

  • Page 84: Position Of Head Frame Plate/Stitch Plate In X-Direction

    Adjustment: • Slightly untighten screws a (T20). 4.2.2 • Apply angled eccentric key 031563.50.00 at eccentric engagement bore b to position head frame plate. • Retighten screws a. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 84 von 178...

  • Page 85: Presser-Foot Settings

    • Ensure that presser foot and stitch plate are parallel. • Retighten screw b. Note: The presser foot height is read by the PCBA-Dual feed sensor and does therefore not require mechnical adjustment as with previous models. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 85 von 178...

  • Page 86: Presser-Foot Fixation

    • Ensure that presser foot sole and stitch plate are parallel - align if required. • Use 3/8' markings on stitch plate for reference. • Retighten screw c. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 86 von 178...

  • Page 87: Needle Settings

    The adjusting screw g must only be used for the parallel setting of the needle bar and presser foot bar. It mustn't be used for the setting of the needle/hook distance! Setting of needle/hook distance (see 4.5.4). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 87 von 178...

  • Page 88: Needle Distribution

    • Retighten screw b. Test: • Attach presser foot 1D. • Set to maximum stitch width. • Needle mustn't touch the right or left side of the stitch plate BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 88 von 178...

  • Page 89: Zigzag Stitch Width Limiter

    • Needle bar support mustn't touch the zigzag stitch width limiter a (picture 4.4.3). 4.4.3 Adjustment: • Loosen screw b (T10). • Position limiter a. • Retighten screw b. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 89 von 178...

  • Page 90: Hook, Needle Drive And Feed-Dog Movement Synchronization

    • Turn belt pulley until base shaft can be pinned against lift cam with the 3.0mm pinning tool 007937.50.00. • Retighten first screw d (T10) on belt pulley. • Remove gauges. • Retighten second screw d (T10) on main shaft belt pulley in rotating direction. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 90 von 178...

  • Page 91: Loop Lift

    (no play, no clamping). • Use gauge to remove clamp. • Retighten second screw in rotating direction. • Check again and repeat setting if required. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 91 von 178...

  • Page 92: Needle / Hook Distance

    • Carefully nudge stitch plate in required position with the aid of an angled torx spanner T6. • Retighten screw b (T6 screwdriver). Note: We recommend to use a magnifying glass to ensure accurate setting. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 92 von 178...

  • Page 93: Needle Height

    Note: If the distance plate b deviates from its nominal position c = 2, the needle positioning pin d needs to be replaced. This is to applay for all 7 Series machines. • Remove the distance gauge a. • Replace the distance gauge with the needle stop position screw d (T6) to set the height.

  • Page 94: Feed-Dog Settings

    Without sideways motion feeding (B750, B710) • Turn handwheel until feed-dog at its highest point. • Untighten screws e (T6). • Move feed-dog into the specified position. • Retighten screws e. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 94 von 178...

  • Page 95: Dual Feed: X-Direction Positioning Against Main Feed-Dog

    Without sideways motion feeding • Untighten screw c (T10). • Use eccentric key 001361.70.00 in eccentric engagement bore d to adjust the lateral positioning. • Retighten screw c. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 95 von 178...

  • Page 96: Leveling Of Main Feed-Dog (0.9-1.0Mm)

    • Retighten screw d (T8) and check the height using gauge 398024.03.1+. • Repeat adjustment if necessary. Note: Turning clockwise > feed-dog level is lowered. Turning counterclockwise > feed- dog level is lifted. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 96 von 178...

  • Page 97: Main Feeding Balance - Mechanical Basic Setting

    • The first tooth d of drive gear b must gear into the first gap of the toothed segment e. • Use spring pressure to reposition spherical bearing h to the left into the motor holding plate. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland...
  • Page 98 • Retighten screw g to fix drive gear b at stop c. • Remove pinning tools. • Refit PCBA-base. To fine adjust, refer to Service Program, Test BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 98 von 178...

  • Page 99: Feed-Dog/Dual Feed Synchronization

    • The dual feed should lie flush against point e at Synchroplate f without play or clamping. Setting: • Loosen screw g (T10). • Move dual feed into the specified position. • Retighten screw g. • Remove Synchroplate and pinning tools. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 99 von 178...

  • Page 100: Dual Feed Balance - Basic Mechanical Setting

    Turn adjusting screw a until the distances between the drive belt flange and the adjusting hub are even. • Carry out BDF Balance fine adjustment in Service Program 6b BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 100 von 178...

  • Page 101: Clutch Carriage / Thread Cutter

    • Refit air duct (see 3.2.11). Only with B780. • Refit freearm cover plate, freearm cover, rear cover, and head cover (see 3.1) • Test sew and test thread cutting. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 101 von 178...

  • Page 102: Clutch Carriage

    • With the lever in this position, retighten the two screws (T10) on the connecting strap between clutch mechanism and cutting unit release lever. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland...

  • Page 103: Timing Of Clutch Carriage

    • Retighten the second screw. Then remove all gauges. Turn the handwheel and retighten the first screw in direction of rotation. • Refit all the covers. • Sew-off, also using the thread cutter. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 103 von 178...

  • Page 104: Thread Cutter

    Refit and re-tighten screw c (T8 angled torx) and nut d (open-end or ring wrench 5) on thread guide plate/thread stop. • Carry out a manual functioning check. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 104 von 178...

  • Page 105: Synchrinising Disc

    (BDC = 0°). • Place synchronizing disc against circlip. • Retighten screw a slightly. • Remove loop lift gauge. Warning: Don’t tighten to hard screw a of the synchronising disc. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 105 von 178...

  • Page 106: Threader

    The threader head can be properly adjusted by moving it up, or down. 734101.50.00 • Retighten needle bar guide adjusting screw 17 (T8) and check setting (4.10.1). • Refit basting solenoid housing. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 106 von 178...

  • Page 107: Basting Device

    Loosen needle bar guide adjusting screw 17. 734101.50.00 • Center needle bar bore within clutch-bolt clearance 4. • Retighten needle bar guide adjusting screw 17 (T8). Refit basting solenoid housing. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 107 von 178...

  • Page 108: Checking The Timing Of Disengagement

    • Run machine at highest speed to test basting magnet in left and right needle positions Note: If functional test fails in one, some or all needle positions, recheck the setting of the cushioner position and the needle bar guiding and adjust as required. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland...

  • Page 109: Thread Regulator

    Check tension: • Thread thread regulator with a 30cm long bit of thread. • Attach the two thread ends to the BERNINA tension spring scales (006038 50.00). • Slowly move the scales up. • On moving the regulator spring, the tension value must be 12 – 15 g.

  • Page 110: Thread Tension

    4.12.1 Upper-Thread Tension 6j Automatic Upper Thread Tension: • Use a DMC 50 BLANC cotton thread (recommended by BERNINA, also refer to Service Info, Ref-# 18249, in Infogate) to thread the machine. Step 1: • Attach the 30.6-gram gauge to the upper thread (see picture 1).

  • Page 111: Lower Thread Tension (Basic Setting)

    Note: Incorrectly or unevenly filled bobbins can affect the stitch quality and impair the functioning of the lower thread sensor. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 111 von 178...

  • Page 112: Lower-Thread Sensor Position

    If the lower-thread indicator doesn't work flawlessly, check the state of the bobbin, especially the inner and outer reflectors on the bobbin. If the bobbin is in mint condition, replace the lower-thread indicator unit. BERNINA International AG Seestrasse 161 CH-8266 Steckborn...

  • Page 113: Chapter 5 - Service Program

    2 = Screen Menu 3 = Sensors Menu 4 = Signals Menu 5 = Motors Menu 6 = Settings Menu 7 = Embroidery Module (only BERNINA 11 = Check-Out 790/750/720) BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 113 von 178...
  • Page 114 BERNINA 770 / 720 1 = Service-Info 2 = Screen 3 = Sensors 4 = Signals 5 = Motors 6 = Settings 7 = Embroidery Module 11 = Check-Out (only BERNINA 780/750) BERNINA 740 1 = Service-Info 2 = Screen...
  • Page 115 Selecting a keyboard a: Upper case letters b: Lower case letters c: Numbers, special characters and punctuation marks d: Special marks BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 115 von 178...

  • Page 116: Menu 1 - Service Information

    Technical data (1 – 10). Note: • Using the virtual keyboard, technical data can be entered in the page. • The entered data gives the technician information on already made improvements. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 116 von 178...

  • Page 117: Machine Operating Time Data

    Total number of stitches using BSR • Total number of embroidery stitches • Stitches since last lubrication • Stitches since last service 1e BSR (BERNINA Stitch Regulator) Data What to test: The BSR foot must be attached and connected. • Serial Number • Chassis Number •...

  • Page 118: Machine Servicing Data

    Service interval • The stitch counter triggers a reminder after 3,000,000 stitches: Please take your machine to a BERNINA dealer for servicing. Important: • Remember to always reset the counter (cleaning interval) after servicing or repairing.

  • Page 119: Saving / Loading Customer Data

    BERNINA USB memory stick. • Load the Customer settings Loading of customer data to the machine. Note: Connect BERNINA USB memory stick and select required button. Remove the stick after saving of data has been confirmed. 1h Customer Data What to test: •...

  • Page 120: Dealer Data

    • Dealer data can now be entered. • Dealer data can also be read and entered in .txt format from a BERNINA USB memory stick. Important: The file must be named "dealerdata.txt" (see example below). • The dealer-related data will automatically appear on the screen when a maintenance reminder is triggered.

  • Page 121: Menu 2 - Display, Buttons

    * = Red, Green and Blue 2a Touchscreen Calibration What to test: • Touch 'Calibrate' to start the test. • To calibrate the touchscreen, use the BERNINA stylus to touch the 3 crosses as required • Touch to save and return. • Touch to close without saving.

  • Page 122: Lc Display (Screen)

    To return to menu 2, touch Repair notes: • Clean LCD and touchscreen. Attention! Never use alcohol, petrol, spirits or any corrosive fluids, or abrasive pastes or abrasive cleaners! BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 122 von 178...

  • Page 123: Rgb (Red, Green And Blue) Screen

    To return to menu 2, touch Repair notes: • Check cables for deformation and/or wear and tear. • Replace PCBA-RET if any of the buttons don’t light up. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 123 von 178...

  • Page 124: Led's And Brightness

    Check all connectors. • Check cables for deformation and/or wear and tear. • Check connectors P-38 and P-3111 on the PCBA-Base. • Replace the LED’s. • Replace the PCBA-Base. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 124 von 178...

  • Page 125: Menu 3 - Sensors (Mounting Locations In The Machine)

    Check correct positioning of PCBA Threader. The PCBA Threader is held in position with a pin and fastening screw 007752.50.34 (T10) in the needle bar support. • If the sensor doesn't respond, replace the PCBA Threader Sensor (see 3.2.15). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 125 von 178...

  • Page 126: Overlift Presser Food Switch (Presser Foot Height Sensor)

    Incorrect reading of presser foot height! "0" will be displayed if the presser foot sits on the stitch plate in most cases. • Check the basic setting of the presser foot height in Service program 6h. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 126 von 178...

  • Page 127: Lower-Thread Sensor

    Repeat the test using a new bobbin. • Check on correct position of PCBA-Lower-Thread-Sensor. (see 3.2.15) • Check cables for deformation and/or wear and tear. • Replace PCBA-Lower-Thread-Sensor (see 3.2.20). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 127 von 178...

  • Page 128: Feed Dog Drop

     Unplug PCBA-Base connector.  Replace PCBA-Detection.  Replug PCBA-Base connector.  Refit PCBA-Detection in required position and retighten fastening screw (T20).  Refit the covers (see 3.1) BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 128 von 178...

  • Page 129: Dual Feed Recognition Sensor

    Calibrate the presser foot height (Test • If the sensor doesn't respond, replace the PCBA Dual Feed Sensor (see 3.2.17). • The support ABC sensor (presser foot recognition) might also be affected. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 129 von 178...

  • Page 130: Bobbin Winder Switch

    The color of the bar changes from yellow to green. • Press to return to menu 3. Repair notes: • Check cables for deformation and/or wear and tear. • Replace winder • Replace PCBA-Base (see 3.2.7). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 130 von 178...

  • Page 131: Free Hand System Fhs

    • Check cables for deformation and/or wear and tear. • Check if in the area of the sensor on the PCBA-Base no cables are exposed. • Replace the sensor if it doesn't respond. BERNINA International AG Seestrasse 161 CH-8266 Steckborn...

  • Page 132: Menu 4 - Signals

    Stitch width and stitch length knob(s) b) Functions of keys and buttons on machine c) Start-/stop slide (SSU) d) Foot control e) PS2 Interface Upper thread sensor g) BERNINA Stitch Regulator (BSR) h) PCBA-Position Speaker USB ports k) Basting solenoid Presser foot recognition...

  • Page 133: Functions Of Keys And Buttons On Machine

    The bar will fill accordingly. • Press to return to menu 4. Repair notes: • Check cables for deformation and/or wear and tear. • Replace PCBA Left Front Cover (see 3.2.1). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 133 von 178...

  • Page 134: Foot Control

    Check if the regulator is properly hooked and if it actuates the actuating lug. • Check if the regulator spring is properly set (see 4.11). • Replace PCBA-RET (see 3.2.6). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 134 von 178...

  • Page 135: Bernina Stitch Regulator (Bsr)

    4g BERNINA Stitch Regulator (BSR) What to test: • Attach BSR foot. • Select test 4g. • Lower presser foot. • Press the icon to start the test. • Place fabric under the presser foot. • Move the fabric in different directions.

  • Page 136: Mechanical Fine-Adjustment Of Synchronization Disk

    Turn synchronizing disk until signal 1 blanks. Position: between 25° and 27,5°. • Retighten screw a (not too hard). Attention: Don't tighten screw a of synchronizing disk too tight. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 136 von 178...

  • Page 137: Speaker

    If 'Test Failed' message appears: • Repeat the test using another USB cable. • Check the client and host ports on the machine. • Replace PCBA-Base (see 3.2.7). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 137 von 178...

  • Page 138: Basting Solenoid

    Press to return to menu 4. Repair notes: • Check plugs and cables for deformation and/or wear and tear. • Replace basting solenoid. • Replace PCBA-Base (see 3.2.7). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 138 von 178...

  • Page 139: Presser-Foot Recognition

    1C, 20C, 40C 5.5mm feet e.g.: Feet 2A, 5, 16, 18 Straight stitch foot Darning foot e.g.: Feet 13, 35, 38, 43, 53 5.5mm Dual feed foot BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 139 von 178...
  • Page 140 Press the presser foot indicator (marked in red) at top left. • The currently attached presser foot will be displayed in the box top left, along with all other feet on further 6 pages. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland...

  • Page 141: Bsr Foot Interface

    Repair notes: • Check BSR plug and connector. • Check cables for deformation and/or wear and tear. • Replace BSR foot. • Replace PCBA Accessories Connector (see 3.2.18). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 141 von 178...

  • Page 142: Menu 5 - Stepping Motors (Mounting Locations In The Machine)

    Swap connectors with the presser-foot pressure stepping motor to check if the fault is with the motor or the PCBA-Base. Caution! Disconnect from the power supply. Do not disconnect or reconnect when the machine is powered. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 142 von 178...

  • Page 143: Presser-Foot Pressure Stepping Motor

    Do not disconnect or reconnect when the machine is powered. Do not connect the stepping motor to the stitch length or the dual feed stepping motor, as these two motors work with higher amperage! BERNINA International AG Seestrasse 161 CH-8266 Steckborn...

  • Page 144: Pinning Positions Of All Stepping Motors

    5. Repair notes: • Check plugs and cables for deformation and/or wear and tear. • Replace the winder motor (see 3.2.4). • Replace PCBA-Base (see 3.2.7). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 144 von 178...

  • Page 145: Stitch Length Stepping Motor

    Swap connectors with the dual feed stepping motor to check if the fault is with the motor or the PCBA-Base. Caution! Disconnect machine from the power supply. Do not disconnect or reconnect when the machine is powered. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 145 von 178...

  • Page 146: Sideways Motion Stepping Motor

    Check plugs and cables for deformation and/or wear and tear. Caution! Disconnect machine from the power supply. Do not disconnect or reconnect when the machine is powered. . BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 146 von 178...

  • Page 147: Menu 6 - Adjustments

    Note: In order to ensure the carrying out of all crucial adjustments and calibrations, follow the check list in menu Note: Do not run a threaded machine without fabric! BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 147 von 178...

  • Page 148: Balance

    • The basic value is 0, the setting ranges from +4 to -4. • Press to save the value. Note re feed-direction adjustment: • button = forward, button = backward BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 148 von 178...

  • Page 149: Fine-Adjustment

    • The “9” must be stitched without gaps between the stitched lines. What to adjust: • Turn balance cam a (T10) to adjust until the “9” is stitched properly. Turn CW Turn CCW BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 149 von 178...
  • Page 150 Note re rotating direction when adjusting: • Rotate the balance cam a clockwise = the leaf pattern pulls together • Rotate the balance cam a counterclockwise = the leaf pattern pulls apart.  BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland...

  • Page 151: Fine-Adjustment (Sideways Feed)

    • Turn balance cam a CW or CCW to adjust until the pine is stitched properly. • Points 1 and 2 must be flush. End point 2 may however be 1mm above level Turn CW  Turn CCW BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 151 von 178...

  • Page 152: Bdf Balance

    • Lower the presser foot. Press the permanent reverse button on the screen. • Sew the second set of 6 repeats in reverse. • The difference in length between the two stitch rows should not be larger than 7.0mm. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland...
  • Page 153 • Turning adjusting screw a counterclockwise will shorten the left side of the diamond stitch pattern while the right side of the diamond pattern will be lengthened. BERNINA International AG Seestrasse 161 CH-8266 Steckborn...

  • Page 154: Buttonhole Calibration

    • Check foot recognition in test 4l. • Replace presser foot. • Check plugs and cables for deformation and/or wear and tear. • Replace PCBA-ABC Sensor (see 3.2.16). • Replace PCBA-Base (see 3.2.7). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 154 von 178...

  • Page 155: Thread Cutter Clamping Mechanism (Magnet)

    • Press to return to menu 6. Repair notes: • Check cables for deformation and/or wear and tear. • Replace complete clutch carriage. • Replace the PCBA-Base. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 155 von 178...

  • Page 156: Thread Cutting Process

    Move to intermediate position and cut thread. Separate upper and lower 185° thread Move to needle stop position up. Restore thread tension 220° Test Done Tension sequence finished 220° BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 156 von 178...

  • Page 157: Upper-Thread Tension Reset To Default

    • If the answer is Yes, press to reset the upper-thread tension to default and to return to menu 6. • If 'No', press to return to menu 6. The tension values remain unchanged. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 157 von 178...

  • Page 158: Resetting To Factory Settings (Reset All)

    6. The sewing settings remain unchanged. IMPORTANT: It is essential to save all the customer’s data on a BERNINA USB data stick before resetting to factory settings! See data saving in test 6h Presser-Foot Height And Presser-Foot Pressure...

  • Page 159: Automatic Upper-Thread Tension

    • Select the thread used for the thread tension adjustment (DMC 50 Nr. 50, 100% Cotton, Color blanc (white)) • A 'Successful!' message will appear on successfully completed adjustment. • Press to return to menu 6. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 159 von 178...

  • Page 160: Start-/Stop Unit (Ssu) Slide Control Calibration

    Repair notes: • Check slider for dust or dirt and smooth mechanical running. • Replace PCBA Front Cover (see 3.2.1). • Replace PCBA-Base (see 3.2.7). BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 160 von 178...

  • Page 161: Bsr Sewing Mode

    Y-direction belt tension o) X-direction belt tension A detailed description of the embroidery module service program can be found in the Embroidery Module Service- and Maintenance Manual. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 161 von 178...

  • Page 162: Menu 11 - Check Out

    5) Buttonhole calibration, menu 6c 6) Cleaning and servicing intervals, menu 1f After completion and confirmation of the last test, the check-out program will return to the main service menu. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 162 von 178...

  • Page 163: Chapter 6 - Lubrication Diagram

    Chapter 6 – Lubrication Diagram = Klüber OY 100 (002779.70.01) = Velocite 6 (033567.50.01) = Klübersynth UH1 14-1600 (002779.72.02) Head frame Dual feed BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 163 von 178...
  • Page 164 Threader mechanism / Needle drive BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 164 von 178...
  • Page 165 Toothed-segment needle-bar support Upper Thread Tension Unit Dual feed crank shaft BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 165 von 178...
  • Page 166 Dual feed main shaft lift and advance cam Hook Shaft / Hook Race / Hook / Hook Driver see SI # 48554 BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 166 von 178...
  • Page 167 Feed-dog fork Base shaft / feed-dog lift and advance cam Feed-dog crank shaft BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 167 von 178...

  • Page 168: Chapter 7 - Firmware Update

    Update files are available for downloading from Infogate. • The update files for BERNINA 790, 770, 740 and 720 cannot be downloaded to one BERNINA USB stick. Note: If the files are saved in a folder or subfolder, the machine will not be able to find them and will consequently not be able to update.
  • Page 169 USB memory. level of the USB memory (root No valid Updates on USB Stick directory). Defective or incompatible USB Use a BERNINA USB stick. stick. Check functioning of USB stick on a pc. Is the USB stick connected?

  • Page 170: Update - Alternative Access

    After the machine has been switched on, the update process will start and check the data on the USB stick. Note: On completion of the manual update procedure, the machine must be started manually. BERNINA International AG Seestrasse 161 CH-8266 Steckborn...

  • Page 171: Chapter 8 - Maintenance Guidelines

    • Defined wear-and-tear parts are subject to a charge; the parts declared in the spare-parts-warranty extension (Bernina warranty provision) are excepted. • Compliance with maintenance intervals allows system functioning to be ensured and increases the service life of the sewing and embroidery machines.

  • Page 172: Implementation Of The Maintenance Intervals

    • Service entries must be made by the technician in the Service Program after maintenance or repair work – if not, the maintenance stitches will not reset to zero. • The same holds true for the cleaning-stitch reset. BERNINA International AG Seestrasse 161 CH-8266 Steckborn...

  • Page 173: Wear-And-Tear-Parts Definition

    • In the case of intensive use for which the machine was not designed, increased wear-and-tear of parts cannot be ruled out. • In order to ensure continuously defect-free operation of the sewing and embroidery machine, BERNINA recommends replacing the parts according to the table (8.4.2) once the tenth maintenance interval is reached. •...

  • Page 174: Operating-Time-Related Parts

    Spherical bearing Note: The X in the 8th position of the article numbers serves as a placeholder for the modification indicator (a number from 0-9) The counting of the modifications starts at 0. BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland...

  • Page 175: Maintenance Checklist

    • Read out the stitch and hour counter and enter on the Service Report. Customer data backup in BERNINA 790 Service Program 1g. Connect BERNINA USB memory stick and select required button. Remove stick after confirmation by the machine. • Save the customer settings = Customer data saved onto the storage medium •...

  • Page 176: Functional Check

    • Needle bar support / needle bar Smooth running of the machine – mechanical • Swing bearing ease of movement • Bevel gears • Bobbin carrier / hook • Drive belt tensions BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Page 176 von 178...

  • Page 177: Maintenance Checklist Bernina 790 / 770 / 710 / 720

    8.5.4 Maintenance Checklist BERNINA 790 / 770 / 710 / 720 Front and rear cover Covers to be removed Base casing Stitch plate Hook Parts that must be removed Bobbin carrier Recommended parts according to Tear-and-Wear Parts Definition Free-arm area...

  • Page 178: Embroidery Module

    Maintenance Manual of Embroidery Module. Sewing-off Cleaning Covers Final check Is the set of accessories complete? Document Revision History Date Version Description Author March 2015 First release in German Dieter Uhmeier BERNINA International AG Seestrasse 161 CH-8266 Steckborn Switzerland Seite 178 von 178...

Table of Contents

Save PDF