Hi everyone - long time lurker and first time poster 😀 I recently got back interested in old hardware and want to show the kids some old games I used to play. I recovered my old PC2386 from my parents loft. I have fond memories of this unusual machine. It was my first fairly capable PC – and my Mum got it from Amstrad on staff purchase when she used to work there.

When I got it out of the loft the power supply had failed, which I was able to repair by changing some leaky caps and a faulty opto-isolator. After that the power supply seemed stable under a test load and the voltages were well within tolerances.

To my extreme surprise once I’d reassembled the machine it started straight up! The hard drive spun up and I was able to boot to a floppy. I entered the appropriate BIOS settings and restarted and it then booted from the 65Mb MFM drive for the first time in about 30 years. It did seem too easy – and of course it was!

After a few hours of use – checking for hard drive errors and diagnostics (which all passed) the screen suddenly went blank half way through start up after a soft reboot. And that was it. I powered it down – and when I switched it back on I get stripes on the screen and apart from a very brief flicker of the lights on the keyboard, that’s it. I’ve removed all cards from the machine – no change. The stripes appear instantly the second power is applied to the board so it’s as if it is stuck in reset and not even trying to initialise.

The board doesn’t seem to feature POST codes so my ISA diag card reveals little other than all of the voltages are correct, the clock is present and the reset line briefly goes high after switch on then goes low.

I can see activity on the address and data lines and the 386DX gets warm so I assume the CPU is running. Other chips seem to get warm too and none get overly hot to the touch. I have tried changing the SIMMs for a separate matched set of four and that makes no difference at all. The board itself is in very good condition. There is no corrosion, no shorted capacitors – and no MOSFETs. Oscillators all seen to be generating correct frequencies.

I may be being optimistic – but the fact it did work and that I can still see lots of activity on the address and data lines makes me hope that the major components are OK but something has failed and is preventing initialisation kicking off. I’ve read on other threads that displaying stripes on this machine indicates a RAM problem, but I’m not convinced as I’ve tried two sets of SIMMs and because the stripes appear immediately upon switch on. I suspect it’s more that the GPU just isn’t being initialised at all

I’m running out of expertise on this though – and would be grateful for any suggestions of further checks I can perform to try and narrow this down. It's driving me crazy!

Cheers
Mark