Editing Sinclair ZX Spectrum Service Manual

The '''Sinclair ZX Spectrum Service Manual''' is Sinclair Research's official service documentation for the 16K and 48K [[Sinclair ZX Spectrum]] and the [[Sinclair ZX Spectrum+]]. Like the [[Sinclair QL Service Manual]] it is written at full component level: as well as fault diagnosis it contains complete parts lists, so every capacitor, resistor, diode and transistor designator and value on the main board is documented — '''and it is documented separately for each board issue''', which matters because the Spectrum's component complement genuinely changed between issues.

It is the primary reference for [[Sinclair ZX Spectrum Capacitor Replacement Guide]], [[Sinclair ZX Spectrum General Maintenance]] and [[Sinclair ZX Spectrum Troubleshooting Guide]].

The copy hosted here is the re-typeset Revision 1.3 edition prepared by Brendan Alford for the Spectrum For Everyone project, which combines the original manual with both of Sinclair's supplements in one document. One passage — the DC-DC converter modification in Supplement No. 1, section 9.2 — carries an editor's note warning that Sinclair's printed instructions for that modification are wrong and should not be followed; the parts list in section 9.13 is the reliable record of what each board issue actually carries.

== Contents ==

{| class="wikitable styled-table" style="width:85%; text-align:left;"
! Section !! Covers
|-
| Section 1 || System description — Z80A CPU, memory organisation, read/write operations, I/O, TV picture generation, keyboard scanning, tape interface, loudspeaker, and the on-board power supplies
|-
| Section 2 || Disassembly and assembly
|-
| Section 3 || Setting up and system test — the internal voltage check table, colour adjustment, sub-carrier and 14 MHz oscillator alignment
|-
| Section 4 || Fault diagnosis: getting started — test equipment, modification history, per-issue modifications, the 16K-to-48K upgrade and its link settings
|-
| Section 5 || Fault diagnosis: PSU and memory — the basic check table, the memory check procedure and the bit-to-IC fault table, keyboard structure
|-
| Section 6 || Fault diagnosis: input/output — symptom-by-symptom lists covering video, colour, keyboard, regulator coil and speaker
|-
| Section 7 || Colour, repair and upgrades — LM1889 pin signals, 16K-to-48K upgrade detail
|-
| Section 8 || Parts lists for Issue 2 and Issue 3 boards
|-
| Section 9 || Supplement No. 1 — Issue 4A, 4B, 5 and 6A boards, and their parts lists
|-
| Section 10 || Supplement No. 2 — Spectrum to Spectrum+ conversion
|}

== Board issues it covers ==

Sinclair shipped Issue 1, 2, 3, 3B, 4A, 4B, 5 and 6A boards; no Issue 4 and no Issue 6 were ever issued. The manual body covers Issue 1 to 3B and Supplement No. 1 covers the rest. Capacitor values are '''not''' constant across that range — for example C1–C8 are 47 nF on Issue 2 and Issue 3 but 22 nF from Issue 4A onwards, and C44/C45 are not fitted at all on Issue 5.

<pdf> File:Sinclair ZX Spectrum Service Manual.pdf </pdf>

Download the Sinclair ZX Spectrum Service Manual here: [[:File:Sinclair ZX Spectrum Service Manual.pdf|Sinclair ZX Spectrum Service Manual.pdf]]

== Related pages ==

* [[Sinclair ZX Spectrum]]
* [[Sinclair ZX Spectrum Capacitor Replacement Guide]]
* [[Sinclair ZX Spectrum General Maintenance]]
* [[Sinclair ZX Spectrum Troubleshooting Guide]]
* [[Sinclair ZX Spectrum+]]

[[Category:Sinclair Computers]]
[[Category:Service Manuals]]