Dump some vinegar onto the area to neutralize the residue (it's not actually acid, but an alkaline substance), let it sit for 10-15 minutes, and then follow up with some isopropyl alcohol and a soft brush... an old toothbrush works well for such things.

The only real point of concern I see is that one short trace on the top side... it may still be OK, but just for good measure I would recommend scraping/sanding it lightly to get down to good copper, and then tin it with some fresh solder. Everything else should clean up without much fuss.

^ yep vinegar is the way to go (I also use lemon juice some times)
I think you'll easily save this mobo, after a good cleaning all you need is to maybe fix the diagonal trace at the battery area and maybe re-solder the keyboard connector

A friend recommended that too. I will do it tomorrow when i return from college. I also need to check for solder i think I'm out.

Also yeah, i think so too 😀
I will also replace the kb connector if i find a spare.

Also its an ETEQ model.
I have an 80387DX-20 but it cant fit into the secondary socket. Found an image of the board on a vogons topic:

http://i54.tinypic.com/2psexhs.jpg

Ok ive done it and the greenish patina is now removed from all components, except the kb connector.
I have scraped down the line to copper and will protect it will some solder latter 😀

The protective layer did get a bit whiteish because of alcohol but its all good.

Will post the result after the board is completely dry. Ive blown the water away with a compressor.

What battery should i use as a replacement?

[Edit]

MoBo works, even loads up to 32 megs of ram 😁
But the keyboard connector seems to be corroded. I will try to clean it and than see if i get contact. The keyboard diodes light up normally and turn off at power up but the screen reports a kb error and it doesnt accept commands.

Also, do i need a math co processor?

Wait, did you say "scraped"? That doesn't sound very healthy to me. Traces that have been exposed to battery leakage can be fragile and are easily sliced through or can lift away from the motherboard. Cleaning with a soft bristled toothbrush is much gentler on the traces.

I have used diet coke on a motherboard with a leaked battery - the leak wasn't big, but enough to make the motherboard not detect the keyboard. Since then it works like charm.

The line was heavily corroded, even so much it lost contact at one part, hence the need to softly scrape the corrosion off.

Good news! I have fixed the damaged line! 😁

Bad news, the board wont work any more 🤣

Well, it probably isn't anything major, considering it was working before you patched the trace. Maybe it's something simple like a stray glob of solder bridging something it shouldn't?

Any update on this how it went? Did you save the board in the end somehow?

I've got the same problem, only I am not sure what the real damage is. The status now is that the motherboard does not start/beep at all.
Only thing is that the CPU heats very much, 30 seconds after I start the power source.

Is it corect that the motherboard does not start without a battery? Not even beep or start the monitor?

Meister wrote:

Any update on this how it went? Did you save the board in the end somehow? […]
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Any update on this how it went? Did you save the board in the end somehow?

I've got the same problem, only I am not sure what the real damage is. The status now is that the motherboard does not start/beep at all.
Only thing is that the CPU heats very much, 30 seconds after I start the power source.

Is it corect that the motherboard does not start without a battery? Not even beep or start the monitor?

Is there any corrosion on the other side of the board?

The other side is fine. No corrosion at all. I'll bring the board to a technician next week to be checked. I've seen videos on youtube where really messed up PCBs got cleaned up proffesionally. Maybe there is hope for this mb to be saved.

The board should start with out an battery, unless its an odin/dallas rtc one.
The problem with leakage is that it gets inbetween PCB layers and causes damage there. It spreads trough copper. The board I complained about did not work at all latter after cleaning, probably got damaged lines somewhere in the process.

I think this is my case too! After I removed the battery, I cleaned as much as I could with IPA and tried the external battery connector with 3xAAA rechargeables. But with or without battery, it does not start at all, nor does it beep anymore. Before this it was beeping like crazy but no monitor start either. Need to find someone with a multimeter who can check for interrupted lines in that area. I'm not giving up it yet. Too much history there.

Cleaning the mainboard usually will not magically fix it, maybe in some rare cases when electrolyte created some shorts but didn't damage the traces, but in most cases the traces need to be fixed by covering with solder or soldering wires. The mainboard may no longer beep after cleaning because tiny particles of damaged and exposed copper are removed in that process and a trace loses conductivity then.

Meister - you have two traces (thin and thick) with really heavy damage visible, you can try to repair them, even without multimeter (such heavy corrosion must not be left in current state, even if it works).