This was the luckiest find I had in a while. The schema is absolutely out of proportions (way larger than your board), but the jumpers actually match 100% (th99 was known to have such bugs though, so it's okay)

http://www.win3x.org/uh19/motherboard/show/5409

The photo you took is okay and it is useful for the page in uh19, but if you could take a better photo on a straight surface (like a tabletop), I would really appreciate it. I'm especially requesting this because it's a very poorly documented board.

No problem. This is the best I could do while wrangling my kids, I might be able to take a better one later when they're in bed.

Glad I could contribute, I knew this board was unique for the BIOS alone so I at least wanted to get that out there even if I can't get it working again.

Start with checking the condition of the transistor in the lower right corner of your picture, doesn't look healthy.

DamienC:
Have You progressed forward to revive this board?

I own a board like this and thanks to computerguy08, finally I was able to identify it. Mine works flawlessly 😀
Luckily just a few jumpers was needed to take care with.

According to Your pictures (+ the manual @computerguy08's page), the jumpers next to the left side of the cache ICs are in incorrect position.

Tested 128k & 256k settings as well.

The other thing - I observed Your board is missing 2 resistors: R32 (470 Ohm), R36 (1k Ohm). Interesting there are 2 picture on the manual's page, one yellow PCB + one green PCB. The resistors missing of the former, but exits on the green one..

If You need me to check anything else on the board or measure components etc., just shout me.

Got this board too with bad corrosion on battery corner, SIMM- and ISA-slots are affected too. Reason I wanted this mobo is the chipset, it takes high FSB clocks and is great for overclocking. Good base for a 386-system which can run FastDoom.

Now it's bathing in vinegar and later I'll wash the board and check the traces, hope I'll get it working...

No way I can fix those lines, just too small for my eyes and equipment... 🙁

dj_pirtu wrote on 2024-05-15, 07:17:

No way I can fix those lines, just too small for my eyes and equipment... 🙁

It looks worse than it is, maybe.
The first line can be fixed by a fine resistor leg.
The other two with a fine solder blob. Desoldering braid can help if you do a mistake.

Any fix is better than giving up on the board. 😀

Edit: The second picture doesn't look so bad.
The first line needs a fix, the others are almost fine to me.

Applying solder flux can help to make the connections less brittle.

Personally, I do use liquid rosin here (sold as soldering honey).

dj_pirtu wrote on 2024-05-15, 07:17:

No way I can fix those lines, just too small for my eyes and equipment... 🙁

In this particular case, If you can't solder some very thin wires to restore the broken traces, it is useless to try to tin the traces inflicting more damage to the motherboard. Just hand the board to someone with proper soldering equipment.

I was a little daunted by trace repair at first, but with a $30 soldering pen, $10 magnifying stand, fine tweezers, and plenty of patience, repairing 2 or 3 traces over a short distance isn't so bad. Seems like magic at first, but everything ends up going where you want with a little flux and a little heat in the right spot. Although it's always better to practice on an old modem or something first if you can find the time.

I sacrificed a the motor from a broken floppy drive a couple years back. I got a lifetime supply of trace repair wire out if it.

Gave the board to my friend who has all the equipment and knowledge. I think it's easy job for him. 👍