File:ZX Spectrum Servicing Manual Thorn EMI Datatech 1984.pdf

Servicing Manual for ZX Spectrum — the original loose-leaf service manual prepared by Thorn (EMI) Datatech Ltd for Sinclair Research Ltd, March 1984, copyright Sinclair Research Ltd. 67 pages. OCR'd for the Sinclair community by Andy Dansby.

This edition matters because it carries two sections that are not in the re-typeset Revision 1.3 edition also hosted here:

• SERVICE DATA — the earplug modification, the Kempston hot-plug warning, the voltage-generator modification, the manufacturer's advised modifications, weak sound, tape/sound circuit checks and the alignment procedures.
• REPAIR DATA — a field-service symptom list numbered 1 to 14, added by T.I.S. (Technical Information Services), whose other titles are advertised in the same volume. It is the source of the general check-over procedure, the Kempston-interface guidance, the TR4/TR5/coil warning, the direct RAM check, the keyboard R65–R69 fault, the warm-only fault sequence, the intermittent-fault sequence and the SN1889 substitution note.

The Repair Data is not Sinclair's own text and its opening reliability claim is reported at second hand. It is cited on this wiki as a third-party field-service source, not as manufacturer data.

Described in full on ZX Spectrum Servicing Manual (Thorn EMI Datatech, 1984).

worldofspectrum.net, /pub/sinclair/technical-docs/ — scan OCR'd by Andy Dansby.

Original content copyright Sinclair Research Ltd (rights now with Sky In-Home Service Ltd / Amstrad); the Service Data and Repair Data sections are T.I.S. material. Out-of-print service documentation, hosted here for repair and historical reference. Not under a free licence.