| Model |
Bug |
Repair |
Solution |
|
 |
Sinclair QL |
Ql started with white screen (normally it was ram fault). With minerva ROM the Ql
showed RAM fault at chip two (see photo) but the ram chips were fine. |
Yes |
IC21 74LS245 fault. |
 |
Spectrum 48K |
It started with normal screen but it had some cyan pixels. The message "1982 sinclair research" was corrupted. |
Yes |
Lower memory fault. Changed IC10, 4116 chip with a new one. |
 |
Spectrum 48K |
At start, the screen showed a white border, cyan paper and a tiny black line of pixel
in the middle of the screen. |
Yes |
Lower memory fault. Changed IC10, 4116 chip with a new one. |
 |
Spectrum 48K |
It start, clear the screen but it hang and show white border and black paper. |
Yes |
Upper memory fault.Changed a 4532 chip (32Kx1) to new 4164 (64Kx1). |
 |
Spectrum 48K | The screen showed a lot of colour pixel (there weren't anyone flash pixel). | Yes | Fault Z-80 |
| Spectrum 48K |
It works but fail when load programs. |
yes |
Upper memory fault. Changed a 4532 chip (32Kx1) to new 4164 (64Kx1). |
|
 |
Spectrum +48K |
At start, the screen was alwash black (except a tiny white vertical lines). If I
pressed reset then the screen changed but alwash black. |
Yes |
-5V and +12V line fault.Changed TR4 transistor ZTX650 by a new ZTX651. |
 |
Spectrum +48K |
At start, the screen showed white border and black paper with vertical lines. |
Yes |
Lower memory fault. Changed IC6 and IC9 4116 chips. |
| Spectrum+128K |
It started but no there was no picture on TV. It didn't start correctly (many pixel color on TV). |
yes yes |
+12V fault. TEA2000 didn't have VCC. Changed TR4 (ZTX651) and TR5 (BC557). Z-80 fault. |
|
 |
Spectrum+128K |
No power ON | yes |
No original power supply with only 500mA. 78S05 regulator fault. |
 |
Spectrum+2 |
It started but there was a power supply problem ( I can see it on TV). It didn't start correctly (pixel color and black vertical lines on TV). |
yes yes |
78S05 regulator fault. RAM IC 18 fault. |
 |
Spectrum+2A |
At start, the screen was black with white border. If we pressed reset button, the border changed between white and black. |
yes |
Ram memory fault. Changed IC 3 and IC 4. |
 |
Spectrum+2B |
The screen showed a lot of colour pixel. If we pressed reset button, the screen didn't change. |
Yes |
Ram memory fault. Changed IC 5 and IC6. |
| Spectrum +3 |
Not power ON. It started but there was always the same picture on TV. |
Yes No |
Power supply fault. Fault ULA. |
|
 |
Spectrum ZX81 | The image on TV is very dark. It's necesary to put the TV bright very high to see that ZX81 is working | No | The ULA wasn't broken. Some early ZX81 ULA version didn't make good video signal. |
 |
Timex TC2068 |
It started but there wasn't "1983 TIMEX..." (It started correctly with external ROM
cartridge). Badly picture color on TV. |
yes yes |
ROM fault. It changed the two ROM. Fault capacitor around video circuit. |