First post, by Vegge
So I've had this machine for a while, a Copam PC-501 Turbo. It was dead when I got it, but I was fiddling with it and got it to boot a few times, then moved on to testing other new stuff. But I took it out again last week and it's completely dead. No Irdy signal on the bootcard, no beeps, just dead.
With Supersoft instead, Irdy is lit and it beeps codes, which seems to be "CPU registers and logic" and some DMA faults. After a while it stops beeping and shows 0102, with flickering Irdy.
Heres a video of what it does with the Supersoft/Landmark
I replaced all tantalums on the board just in case and cleaned up some oxide (not much) around the battery. Replaced the 287 socket and added a cr2032 for cmos settings. It might be a little weak though (only 2.55v left at cmos), but 4.5v makes no difference.
All vias are filled with solder so I don't think the battery leaked in there. I have removed crusted solder on some components and reflowed them with a lot of flux to clean it up. As far as I can tell clk signal is present at both 286 and 287 socket.
I've got complete schematics over the board, 16 pages of it. But I really don't know where to begin with this. Anybody got an idea?
more schematics to come...