SINCLAIR ZX Printer Service Manual Edited by Brendan Alford Spectrum For Everyone Website https://spectrumforeveryone.com/ Spectrum For Everyone Facebook Group https://www.facebook.com/groups/spectrum4everyone/ Revision 1.0...
Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ ONTENTS 1 General Information ..........................4 Introduction ............................4 Principle of Operation ......................... 4 2 System Description ............................ 5 Introduction ............................5 Top Cover Assembly ..........................5 Belt and Styli Assembly ........................5 Motor and Gear Train Assembly ......................
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This manual is for use by authorised Sinclair dealers, engineers and representatives as a guide to rectifying faults on the Sinclair ZX Printer. Repair/renewal procedures are limited to those which are specific to this printer; standard procedures for the renewal of electronic components etc., are not included.
Principle of Operation NTRODUCTION The ZX Printer is designed for use with the Sinclair range of microcomputers, and provides a permanent record of any computer output which may be displayed on the TV screen. Because graphic displays always 'join up', long programs, tables of results, elaborate patterns and graphs can be printed out as continuous records, even if carried out in several parts.
Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ YSTEM ESCRIPTION Introduction Top Cover Assembly Belt and Styli Assembly Motor and Gear Train Assembly Control Electronics Board Base Frame Assembly Paper Reel Carrier Assembly Logic Description Circuit Description NTRODUCTION The printer comprises six main assemblies (see Figures 1 and 2):...
Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ OTOR AND RAIN SSEMBLY The motor and gear train assembly drives the following: a) Belt assembly, which produces the printout image b) Paper feed roller, which moves the paper upwards as printing proceeds c) Encoding disc, which functions in conjunction with the control electronics PCB to provide the printout signals to the styli on the belt assembly.
Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ OGIC ESCRIPTION The LED and the photodiode are positioned on opposite sides of an apertured encoder disc. As the disc rotates, the beam of light from the LED is interrupted, thus providing a pulsed signal, the timing of which is governed by the speed of rotation of the disc.
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Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ Transistor TR6 switches the motor on and off. During the last two lines of an 'L print' the motor runs slowly; this is accomplished by switching TR6 on and off, using the time constant R13/C8 in conjunction with the phototransistor output.
Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ AULT IAGNOSIS AND EPAIR The following table is intended as a general guide to the diagnosis and rectification of most of the faults which may occur after considerable usage of the printer.
Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ EMOVAL AND NSTALLATION ROCEDURES Cleaning and Lubrication Top Cover Assembly Belt and Styli Assembly Motor and Gear Train Assembly PCB, Loom and Edge Connector Assembly Encoder Disc Paper Feed Roller Assembly...
Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ To install the top cover assembly: a) If a new tear-strip is to be fitted, insert its retaining lugs into the slots in the top cover, and push down on the tear-strip until it clips into position; ensure that the centre lug is engaged in its slot in the cover.
Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ OTOR AND RAIN SSEMBLY To remove motor and gear train assembly: a) Remove top cover assembly (see para 2.1). b) Remove belt and styli assembly and idler pulley (see para 3.1).
Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ e) Lightly lubricate the ends of the wormshaft with Molycote 44, and press the shaft into its support bushes. f) Support the base insert in the vicinity of the large spur gear, and push the drive pulley shaft fully home into the spur gear boss which protrudes upwards through the base frame.
Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ NCODER To remove the encoder disc: a) Remove the screws securing the base insert, and ease the insert out of the base frame. NOTE: Avoid damaging the LED and its leads which are clipped to the base insert.
Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ APER ARRIER INCH OLLER PRINGS A spring is fitted at each end of the paper reel carrier to force the pinch roller into contact with the paper. Although the springs are identical, they must be fitted in the correct manner (see Figure 5) always remove and install one spring at a time.
Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ LLUSTRATIONS Location of Components (1) Location of Components (2) Top Cover and Base Insert Attachment Points Setting Up Drive (Gear) Train Pinch Roller Springs Logic Circuit Diagram Circuit Diagram...
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Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ Figure 1 Location of Components (1)
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Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ Figure 2 Location of Components (2)
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Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ Figure 3 Top Cover & Base Insert Attachment Points Figure 4 Setting Up Drive Train...
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Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ Figure 5 Pinch Roller Springs...
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Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ Figure 6 Logic Circuit Diagram...
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Sinclair ZX Spectrum Service Manual Spectrum For Everyone https://spectrumforeveryone.com/ Figure 7 Circuit Diagram...