First post, by Susanin79
LOGI PC88XT motherboard — resurrection log
As promised in the “Bought these (retro) hardware today” thread, here’s a dedicated log for bringing a LOGI PC88XT motherboard back to life.
This is the second board from a lot that was sold as non-working / for parts. It carries marks from a previous (apparently unsuccessful) repair. I’ll post diagnosis and repair progress here.
Board description
- Model: LOGI PC88XT
- Chipset: IBM PC/XT-compatible
- CPU: not installed
- FPU: not installed
- ISA slots: 8 × 8-bit
- RAM: up to 640 KB, DIP-16
- BIOS: not installed
Initial inspection
- Damaged traces/pads near the PSU connector
- Evidence of previous repair work
- Bent pins
- C16: missing tantalum capacitor on the +5 V rail
What’s been done so far
- Removed old capacitors
- Cleaned the affected area
- Checked all pads and nearby traces for continuity and lift
- Repaired broken signal/data traces and reinforced any suspicious runs (0.2 mm copper jumpers are used only on signals)
- Traced the primary PSU rails to confirm correct continuity of +5 V, ±12 V, −5 V, GND, and Power-Good
Conclusion
The board has clearly seen better days and shows signs of an unsuccessful past repair, but I’m going to try to bring it back. I started with the obvious: severed traces are restored, questionable ones reinforced, and I’ll reuse the alternative capacitor pads that are in better shape. Next step is to install replacement capacitors, source a CPU, and choose a suitable BIOS (I’ll probably begin with a diagnostic ROM) for the first power-up.
I’ll keep this thread updated.
