Sinclair ZX Spectrum

Sinclair ZX Spectrum Service Manual
Spectrum For Everyone https://spectrumforeveryone.com/
5
7 Fault Diagnosis and Repair – Colour, Repair and Upgrades..................................................................... 36
7.1 IC14 (LM1889) Pin Signals ................................................................................................................. 36
7.2 Repair ................................................................................................................................................ 37
7.3 16k to 48k Upgrade ........................................................................................................................... 37
7.3.1 Integrated Circuits/Link Settings ................................................................................................ 37
7.3.2 Issue 2 Board .............................................................................................................................. 37
7.3.3 Issue 3 Board .............................................................................................................................. 38
7.3.4 Issue 3 Links vs IC Manufacturer and Type ................................................................................ 39
7.3.5 Expansion Memory IC Locations ................................................................................................ 40
8 Parts List ................................................................................................................................................... 41
8.1 Introduction ...................................................................................................................................... 41
8.2 Notes to Parts List ............................................................................................................................. 41
8.3 General Capacitor Change ................................................................................................................ 42
8.4 Case Assembly ................................................................................................................................... 42
8.5 Capacitors - All axial types unless otherwise stated ......................................................................... 43
8.6 Coil .................................................................................................................................................... 44
8.7 Connectors ........................................................................................................................................ 44
8.8 Crystals .............................................................................................................................................. 44
8.9 Diodes ............................................................................................................................................... 44
8.10 Integrated Circuits ........................................................................................................................... 44
8.11 Resistors - All 1/4W, 5% unless otherwise stated ........................................................................... 45
8.12 Transistors ....................................................................................................................................... 46
8.13 Miscellaneous ................................................................................................................................. 46
9 Supplement No. 1 .................................................................................................................................... 47
9.1 Introduction ...................................................................................................................................... 48
9.2 DC-DC Converter Modification ......................................................................................................... 48
9.2.1 Circuit Operation ........................................................................................................................ 49
9.3 Issue 3B Board - (Already covered in existing manual) ..................................................................... 49
9.4 Issue 4 Board - None issued .............................................................................................................. 49
9.5 Issue 4A Board .................................................................................................................................. 49
9.6 Issue 4B Board ................................................................................................................................... 49
9.7 Issue 5 Board ..................................................................................................................................... 49
9.8 Issue 6 Board - None issued .............................................................................................................. 50