Hi!
I have motherboard ECS FA386.
Bios corrupted.
Is anybody have working bios dump?
Best regards, Vladimir.
Hi Vladimir,
I have looked at your FA386-011 BIOS dump and wow, that is one scrambled BIOS!
Looking closer, I noticed that bit 2 is set on every byte in the BIOS. It looks like one of the address lines of the BIOS EPROM is stuck high, so this chip is probably toast.
I searched for boards with the same UM82C480 386/486 chipset to find a replacement BIOS-file and I think I found one. 😀
There is an ECS FA486 board with the same chipset (but a different CPU socket) and it has a BIOS download available on TRW:
https://theretroweb.com/motherboards/s/ecs-fa … 86-rev-1-0#bios
When comparing this FA486 BIOS with your corrupted FA386-011 dump, I found that every byte in the FA486 BIOS that has bit 2 set, is identical to your FA386 BIOS. So I believe these BIOSes are identical and can be used on both the FA386 and FA486 boards. Only the sign-on message shows FA486 instead of FA386, but this is just cosmetic.
I hope you can revive your FA386 with this FA486 BIOS.
Regards, Jan
Hi!
You are right. But I found more serious problem. The chipset is damaged. UM82C482AF has 60 Ohm D2<->GND.
I think motherboard is not repairable. Thanks a lot for you help in finding BIOS for this motherboard.|
Best regards, Vladimir.
Now I'm trying to repair next motherboard GMB-386SAL.
MurVlad wrote on 2025-09-27, 19:10:Hi! […]
Hi!
You are right. But I found more serious problem. The chipset is damaged. UM82C482AF has 60 Ohm D2<->GND.
I think motherboard is not repairable. Thanks a lot for you help in finding BIOS for this motherboard.|Best regards, Vladimir.
Hi Vladimir,
Seeing that all databits 2 in the BIOS are stuck high and you measure a low resistance on dataline 2 at the chipset can’t be a coincidence. Maybe a short-circuit in the BIOS EPROM caused this.
But did you measure 60 Ohm on D2 with the BIOS EPROM chip removed? Perhaps the fault is in the EPROM and not in the chipset…
Cheers, Jan
Chkcpu wrote on 2025-09-28, 12:12:Hi Vladimir, […]
MurVlad wrote on 2025-09-27, 19:10:Hi! […]
Hi!
You are right. But I found more serious problem. The chipset is damaged. UM82C482AF has 60 Ohm D2<->GND.
I think motherboard is not repairable. Thanks a lot for you help in finding BIOS for this motherboard.|Best regards, Vladimir.
Hi Vladimir,
Seeing that all databits 2 in the BIOS are stuck high and you measure a low resistance on dataline 2 at the chipset can’t be a coincidence. Maybe a short-circuit in the BIOS EPROM caused this.
But did you measure 60 Ohm on D2 with the BIOS EPROM chip removed? Perhaps the fault is in the EPROM and not in the chipset…
Cheers, Jan
Hi!
I did measure on D2 with the BIOS EPROM chip removed.
I also tested all the components on line D2. Desoldering them one by one, I found the problem to be in the UM82C482AF chip.
Best ragards, Vladimir.
MurVlad wrote on 2025-09-28, 17:57:Hi! […]
Chkcpu wrote on 2025-09-28, 12:12:Hi Vladimir, […]
MurVlad wrote on 2025-09-27, 19:10:Hi! […]
Hi!
You are right. But I found more serious problem. The chipset is damaged. UM82C482AF has 60 Ohm D2<->GND.
I think motherboard is not repairable. Thanks a lot for you help in finding BIOS for this motherboard.|Best regards, Vladimir.
Hi Vladimir,
Seeing that all databits 2 in the BIOS are stuck high and you measure a low resistance on dataline 2 at the chipset can’t be a coincidence. Maybe a short-circuit in the BIOS EPROM caused this.
But did you measure 60 Ohm on D2 with the BIOS EPROM chip removed? Perhaps the fault is in the EPROM and not in the chipset…
Cheers, Jan
Hi!
I did measure on D2 with the BIOS EPROM chip removed.
I also tested all the components on line D2. Desoldering them one by one, I found the problem to be in the UM82C482AF chip.Best ragards, Vladimir.
Okay, you already did extensive troubleshooting. To bad the chipset is faulty.
Hopefully the next board repair is successful.
Regards, Jan
