Index Burst Verification and Adjustment ....................Track 0 Sensor Adjustment ........................9.10 Asymmetry Verification ..........................TEST P O IN T S .................................... PANASONIC ALIGNMENT DISKETTE ..........................PART II REMOVALS AND INSTALLATIONS ............................12.1 PCB Removal and Installation ........................12.2 Front Plate and Handle Removal and Installation .................
PART. I 1. INTRODUCTION This service manual consists o f tw o parts. Part I covers maintenance description, adjustm ent procedures, and trouble analysis and Part II covers disassembly and reassembly procedures, parts list, and PCB circuits. Part I encompasses maintenance instructions fo r all Floppy Disk Drive (FDD) models. Refer to the highlighted applicable items, and perform maintenance w ork on the FDD.
4. OUTLINE OF MAINTENANCE • The fo llo w in g tools are required fo r maintenance o f an FDD. Alignm ent Diskette A lig nm en t diskette is used fo r head actuator alignm ent and index sensor adjustment. Use the rig h t diskette as shown in Table 8.1.
Read Error Most read errors are soft errors. Data can be recovered by fo llo w in g the recovery procedure in section 5.2. Seek Error Seek errors are caused by the follow ing. Stepper m otor or stepper m otor drive circuit is faulty. Faulty Carriage There are tw o ways to recover from a seek error.
6.3 Trouble Analysis Table Table 6-2 Trouble Analysis Cause $.25indh Item Trouble Collet part fau lty Index detection failure (Replace... Drive m otor control PCB Replace Drive m otor faulty ..Index LED fa u lty Replace Index detector fau lty Replace,..
7. PREVENTIVE MAINTENANCE No preventive maintenance is necessary fo r any FDD under normal conditions. However if adjustments are necessary, the procedures in this manual must be follow ed. • Adjustments (Refer to Table 8-1) (1) Make a read/write head radial adjustment at the specified track. (Sides 0,1) (2) Make an index burst adjustment a t the specified track.
9. ADJUSTMENTS AND VERIFICATIONS Motor Speed Verification (Index Period) (1) Insert a diskette, run the motor, and clamp. Refer to the index period column o f Table 8-1. (2) Step to the specified track. (3) Connect a frequency counter to the INDEX signal: (4) Check th a t the frequency counter readings meet the specifications o f Table 8-1.
Steps(4) to (9) below should be perform ed regardless o f the type, CE or DAD alignm ent diskette used. Use an alignm ent diskette suitable to the type o f FDD to be adjusted according to Table 3-1. (1) Insert Panasonic alignm ent diskette. CAUTION: Be sure to leave the alignm ent diske tte under room co nd itio n s fo r 20 m inutes before adjustm ent.
(7) Move th e stepper m o to r along th e base by hand u n til th e tw o w a ve fo rm s assume approxim ately the same am plitude, and retighten the m ounting screws. (See Fig. 9-2.) (8) Step the head outward (track 0) and inward (track 79), and confirm th a t the adjustm ent has been completed.
Index Burst Verification and Adjustment (1) Insert an alignm ent diskette. Seek to the track specified in the index burst column o f Table (2) Set the oscilloscope in the same conditions as in section 9.7, and set horizontal deflection to 50ps/ division.
9.10 Asymmetry Verification (1) Insert a w o rk diskette. (2) Step to the track specified in the asymmetry item o f Table 8-1. (3) Set the oscilloscope as follows. CH 2 VERT HORIZ TRIG SYNC CH 1 TP 1 1 1 1 !! I I I ! ! ! 0.1 V (4) W rite 1F.
PART. II 12. REMOVALS AND INSTALLATIONS 12.1 PCB Removal and Installation Caution o f the cable leading (1) Remove the fo u r shield plate m ounting screws and take o ut the shield plate. Let the cable pass under the C guide. Hook the cab|e t0 the (2) Remove the one PCB mounting screw.
12.4 Collet Assembly Removal, Installation and 12.3 Track 0 Sensor Assembly Removal and Installation A djustm ent (1) Remove the shield plate as described in section (1) Remove the cartridge guide assembly as described in section 12.7. 12.1 step (1). (2) Remove the lifte r u n it as described in section (2) Disconnect the J3 connector from PCB.
12.5 Clamp Assembly Removal and Installation 12.6 Write Protect Sensor Assembly and Index Sensor Assembly Removal and Installation (1) Remove the fro n t plate as described in section (1) Remove the shield plate as described in section (2) Remove the shield plate as described in section 12.1 step (1).
12.7 Cartridge Guide Assembly Removal and Installation (1) Remove the PCB as described in section 12.1. (2) Remove the handle and fro n t plate as described in section 12.2. (3) Remove the clamp assembly as described in section 12.5. (4) Remove the w rite protect sensor m ounting screw.
12.8 S tepper M o to r A ssem bly R em oval and 12.9 Head C arriag e A ssem bly R em oval and Installation Installation (1) Remove th e head c a rria g e a s se m b ly as (1) Remove the PCB as described in section 12.1.
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Pig ta il leading (1) Pass the pig tail throu g h the pig ta il clamp. (See Fig. 12-9-1.) (2) Locate the side 0 to the outer side and side 1 to the inner side, provide a clearance o f 1mm between them, and place them parallel to each other.
12.10 Drive Motor Removal and Installation When the carriage is on an outer-m ost track : (1) Remove th e c a rtrid g e g u id e assem bly as described in section 12.7. (2) Remove th e th re e d riv e m o to r m o u n tin g Side 1 screws and take o ff the drive m otor from the C Z X >...
12.11 LED Assembly Removal and Installation 12.12 Lifter Unit Removal and Installation (1) Remove the clamp assembly as described in (1) Remove the clamp handle and fro n t plate as section 12.5. described in section 12.2. (2) Disconnect the J8 connector from PCB. (2) Remove the lifte r shaft clamping retaining ring and draw o ut the lifte r shaft.
12.13 Media Lifter Removal and Installation 12.14 M e d ia Sensor A ssem b ly R em o val and Installation (1) Remove th e clamp assembly as described in section 12.5. (1) Remove th e PCB as described in section 12.1. (2) Remove the lifte r shaft clamping retaining ring (2) Remove th e c a rtrid g e g u id e assem bly as draw o ut th e lifte r shaft.
13. EXPLODED VIEW [JU-475-4AGG] * Caution : For transportation, insert the dummy diskette in the drive u nit and close the lever. Remove the dummy diskette before use o f the drive unit. - 23 -...
14. REPLACEMENT PARTS LIST MODEL : JU - 475 - 4AGG Ref. Part No. Part Name & Description Pcs *RSP Remarks YTUF47PK4 PCB Assembly YTFMD02700B4 Stepper M otor YTFJC00521B4 Faston LN41YPHL YTF2C07161B4 Clamp (For Guide Rod) YTF2C08722B3 Stepper M otor Stopper YTF2H12862B2 Shield Plate YTF4H03091B4...
16. SCHEMATIC DIAGRAM [JU-475-4AGG] S ID E D R /W 2 CÖM — FERRITE + 5v o c - ^ - m S f l - 0 + 5 V 33JJ / 25 V - D R I V E SELECT 1 - D R I V E SELECT 2 - ORIVE SELECT 3 - D R IV E SELECT A...