I recently rescued a 486 mobo that had some bad Varta leakage. Luckily the corrosive goop hadn't destroyed any important traces, because the battery was mounted in an area of the board that didn't really have anything nearby. It's important to neutralize the gunk (I used vinegar) and then rinse the area thoroughly with isopropyl alcohol. That will stop any further damage, but depending on how bad the leakage was, some of the PCB traces might've been destroyed.

But that might not be your issue. Check for any blown tantalum capacitors (they're the bright orange/yellow components) -- I had one of them go pop in that 486 board. When they do go, they'll often short out one of the power rails, at which point the PSU will usually shut down. Check the resistance at the motherboard power connectors. If any of the voltage rails (+5V, -5V, +12V, -12V) have an usually low resistance -- say, 100 ohms or less -- then you've got a short somewhere on the board, and 9 times out of 10 that will be due to a tantalum.

kdr wrote on 2020-10-12, 01:11:

I recently rescued a 486 mobo that had some bad Varta leakage. Luckily the corrosive goop hadn't destroyed any important traces, because the battery was mounted in an area of the board that didn't really have anything nearby. It's important to neutralize the gunk (I used vinegar) and then rinse the area thoroughly with isopropyl alcohol. That will stop any further damage, but depending on how bad the leakage was, some of the PCB traces might've been destroyed.

But that might not be your issue. Check for any blown tantalum capacitors (they're the bright orange/yellow components) -- I had one of them go pop in that 486 board. When they do go, they'll often short out one of the power rails, at which point the PSU will usually shut down. Check the resistance at the motherboard power connectors. If any of the voltage rails (+5V, -5V, +12V, -12V) have an usually low resistance -- say, 100 ohms or less -- then you've got a short somewhere on the board, and 9 times out of 10 that will be due to a tantalum.

that would be new to me and i don't own a multi meter and would have no idea what is correct or not without some help and guidance

if you know anyone in uk or i can post it to someone other than uk that has experience and know a lot more or better than me 😁

I've bought a 386 motherboard (with soldered Am386Dx-40) as 'non-working' just for the cache ICs and FPU on it. It had a leaked battery (that I removed for sure) but the harm it caused was insignificant - just a sport or two without corrosion, just removable surface leakage. So I gave it a try.

It starts booting and detects all the equipment but halts once I enter the BIOS and try do something there (sometimes immediately, somtimes allowing me to move step down in the menu). Also it doesn't finish booting halting after it draws the standard 'configuration frame' and starting to write disk related message: I see either D or DI(SK something).

Can it be damaged BIOS for example? Should I try replacing the BIOS IC with the new one (seems like I found the BIOS file I need).