VOGONS


First post, by mjnman

User metadata
Rank Newbie
Rank
Newbie

Hi,
when I poweron this motherboard I hear 3 beep without video output. On the keyboard I could see three led poweron and poweroff and after tha beeps.
I tried to replace the DIPP memories with another 286 worked motherboard but obtain same results (same chipset headland and CPU 286/16 harris). I tried only with anothe worked memory SIMM but same results.
Does anyone have any ideas?
thanks

Attachments

Reply 1 of 8, by PTherapist

User metadata
Rank Oldbie
Rank
Oldbie

Badly corroded traces in top picture from the battery and also all along the top. 2 ISA slots on the right also full of leaked battery contents.

Bottom pic also shows corrosion of traces. Middle pic also shows further corrosion.

That motherboard looks pretty trashed to me, it'd be beyond my capabilities to repair if I owned it, but others who are more skilled with soldering could probably give it an attempt.

Reply 2 of 8, by aha2940

User metadata
Rank Member
Rank
Member

Without knowing the brand and model of the motherboard (or at least the BIOS maker) it's difficult to know for sure what the 3 beeps mean. Depending on the BIOS, they can range from "keyboard problem" up to "memory problems".

Reply 3 of 8, by Horun

User metadata
Rank l33t
Rank
l33t

The traces lined in red are critical no matter who made the board, they supply to the ISA slots.

Attachments

  • bad traces.jpg
    Filename
    bad traces.jpg
    File size
    685.69 KiB
    Views
    227 views
    File license
    Public domain

Hate posting a reply and have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. 🤣 Second computer a 286 12Mhz with real IDE drive ! After that came 386, 486, Pentium, P.Pro and everything after....

Reply 6 of 8, by mjnman

User metadata
Rank Newbie
Rank
Newbie

The three red line are good.
I removed two resistors and four pin jumpers and I found 7 traces around battery interrupted. In the red circle the traces.
Next days I'll try to repair.

Attachments

Reply 7 of 8, by mjnman

User metadata
Rank Newbie
Rank
Newbie

I repaired the seven broken traces but obtaining the same three beeps error when started. I thinking there is a bad IC because when in the first time I powered blowed a capacitor. I think that I can put in the trash. 🙁

Reply 8 of 8, by quicknick

User metadata
Rank Oldbie
Rank
Oldbie

Old tantalum caps blow up all the time, they simply go bad and it's not an indication that there's a bad IC. Seeing that the corrosion is quite spread, it's more likely is that you missed one or more bad trace or via, possibly under the KBC, RTC chip or one of the first ISA slots. Can be a lot of work to diagnose, and almost impossible if you don't have a vacuum desoldering station. Still, I wouldn't put it in the trash; rather keep it for parts or give it away to someone who might be willing to try his luck.