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Table of Contents
Related Manuals for Sinclair ZX Printer
Summary of Contents for Sinclair ZX Printer
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Page 2: Table Of Contents
REMOVAL AND INSTALLATION PROCEDURES SECTION 5 ILLUSTRATIONS -LIST OF ILLUSTRATIONS Fig No. Location of Components Location of Components Top Cover and Base Insert Attachment Points Setting-Up Drive Train Pinch Roller Springs Logic Circuit Diagram Circuit Diagram © Sinclair Research Ltd. -
Page 3: Servicing Manual
This manual is for use by authorised S i n c l a i r dealers, engineers and representatives as a guide to rectifying faults on the S i n c l a i r ZX Printer. Repair/renewal procedures limited... - Page 4 SAFETY MEASURES This instruction manual contains certain WARNING CAUTION notices which MUST be followed by the user to ensure SAFE operation and to retain the equipment in a SAFE condition. All users of the equipment described in this manual MUST have received adequate training in its use and application in order to ensure SAFE AND PROPER USE.
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Page 5: List Of Contents
Principle of Operation INTRODUCTION The ZX Printer is designed for use with the S i n c l a i r range of micro- computers, and provides a permanent record of any computer output which may be displayed on the TV screen. - Page 6 SECTION 2 SYSTEM DESCRIPTION Sub-Section LIST OF CONTENTS Page No. Introduction Top Cover Assembly Belt and Styl i Assembly Motor and Gear Train Assembly Control Electronics Board Base Frame Assembly Paper Reel Carrier Assembly Logic Description Circuit Description INTRODUCTION The printer comprises six main assemblies (see Figures 1 and 2): Top Cover Assembly, ( b ) Belt Assembly, ( c ) Motor and Gear Train Assembly,...
- Page 7 MOTOR AND GEAR TRAIN ASSEMBLY The motor and gear t r a i n assembly drives the f o l l o w i n g : belt assembly, which produces the printout image, paper feed r o l l e r , which moves the paper upwards as p r i n t i n g proceeds, encoding disc, which f u n c t i o n s in c o n j u n c t i o n with the control electronics p.c.board to provide the printout...
- Page 8 N o r m a l l y , the paper feeds through the printer as p r i n t i n g takes place. However, a m a n u a l l y operated paper feed switch is fitted to enable the paper to be fed through without p r i n t i n g , for example, to provide a tear-off m a r g i n at the end of a print-out.
- Page 9 The phototransistor TR9 is soldered to the board, while the LED is on flying leads stuck into the base insert. These items are subject to a lot of tolerances but there should be greater than 200 mV p-p at pin 2 of the ULA when operating.
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Page 10: Fault Diagnosis And Repair
SECTION 3 FAULT DIAGNOSIS AND REPAIR The following table is intended as a general guide to the diagnosis rectification of most of the faults which may occur after considerable usage of the printer. FAULT POSSIBLE CAUSE REMEDY 1. Poor print quality: (a) Vertical zig-zag (a) Worn belt. - Page 11 FAULT POSSIBLE CAUSE REMEDY 3. Motor not operating: (a) Conductor strip (a) Fit new top cover has become loose assembly. In top cover. (b) Motor bevel (b) Check tightness of pinion touching screws and reset motor m o u n t i n g gear mesh (see screws.
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Page 12: Removal And Installation Procedures
SECTION 4 REMOVAL AND INSTALLATION PROCEDURES Sub-Section LIST OF CONTENTS Page No. Cleaning and Lubrication Top Cover Assembly Belt and Sty! i Assembly Motor and Gear Train Assembly PC Board, Loom and Edge Connector Assembly Encoder Disc Paper Feed Roller Assembly Paper Reel Carrier Pinch Roller Springs CLEANING AND LUBRICATION A certain amount of dust from the metallized coating of the paper will... -
Page 13: Top Cover Assembly
If the serrated tear-strip is worn or damaged, this can be removed by pushing out the centre lug (near the spade terminal), lifting the outer edges of the tear-strip and moving it away from the cover to disengage the retaining lugs from the slots in the cover. -
Page 14: Motor And Gear Train Assembly
To install the belt and styli assembly: (a) if a stylus has been removed, place a new stylus over its mounting spigot on the,belt.so,that the leg of the stylus.which has the longer 'foot1 1S outside tlie belt-, secure tlie stYlus °? pushing the retainer cap on to the spigot. -
Page 15: Pc Board, Loom And Edge Connector Assembly
Position the motor on its mounting flange with the orientation mark (on the terminal end of the motor) at the outside, and insert the two attachment screws. If the printer is of the later design, the screws may be tightened fully at this stage. If the printer is of the earlier pattern, the vertical height of the motor must be set as shown in Figure 4;... -
Page 16: Encoder Disc
Remove the two screws securing the p.c.board to the base frame. Gently ease the photodiode and its leads out of the mounting clips on the base frame, and remove the p.c.board, loom, and edge-connector assembly - take care to avoid damage to the LED, photodiode and their leads. -
Page 17: Paper Feed Roller Assembly
Ensure that the encoder disc is clean, and carefully slide its edge under the large spur gear until the spiondle can be seated in its bush. NOTE: Later versions of the p r i n t e r have a m o d i f i e d spur gear on the encoder disc and a flat spring fitted to the s p i n d l e , above... -
Page 18: Paper Reel Carrier Pinch Roller Springs
PAPER REEL CARRIER PINCH ROLLER SPRINGS A spring is fitted at each end of the paper reel carrier to force the pinch roller into contact with the paper. A l t h o u g h the springs are i d e n t i c a l , they must be fitted in the correct manner (see Figure 5) - always remove and i n s t a l l one spring at a time. -
Page 19: Location Of Components
SECTION 5 ILLUSTRATIONS LIST OF CONTENTS Fig No. Location of Components (1) Location of Components (2) Top Cover and Base Insert Attachment Points Setting Up Drive (Gear) T r a i n Pinch Roller Springs Logic Circuit Diagram Circuit Diagram...