First post, by ITzTravelInTime
- Rank
- Newbie
So i got this 64-256k xt motherboard and i want to resurrect it, so i plugged it in with an et4000ax vga card (i have no rgbi compatile monitors for my hercules or ega cards) and i got a screen, but the ram counter during post stops at 064 kb ok and basically the systems hangs from there, i have a post card in one of the isa slots which does not show up post codes because those are unsupported on the xt, but it shows activity on port 80h and so also the cpu, when it comes to 64k on the counter, and it stops writing to port 80h shortly after and it stucks to a value of 0007 most of the times.
So i started swapping parts, i first swapped all the socketed ics on the motherboard because lucly i have some spares for those including a lot of 8088 cpus (but not some working replacement roms and the tools to program those), and ... same beahveour ... so i replaced ram chips multiple times to test all of the compatible ones i have and still the same, i changed vga card and i used a nec v20 and same thing, i also removed ram chips from the vga card to see the problem was the vga card having too mutch of it and no. I have also tried every configuration for the dip switches without luck.
So i am here to ask you for some help thrubble shooting this thing, i have checked all the caps and resistors and they are all fine, also i dont't see any broken traces or damage at a first inspection, but the mobo is an early revision with some patch cables from the factory.
At the end i think that the problem sould be some hidden damage or some bad ics, but i want to hear an opinion from you guys, so let me know if you have any ideas, ecause i am running out of them