Pretty much any sort of very mild acid works for neutralizing battery spew... vinegar is probably the best bet amongst common household items.

You can poke some of the crap out of the vias with a thin sewing needle, don't worry about getting 'em spotless, though, since neutralizing the leakage with vinegar will prevent any remaining particles from causing further damage.

As for a broken pin on a BIOS chip, just carefully solder a little piece of solid core wire to what remains of the leg, to extend it back out to where it should be. You'll have to watch out when you put the chip back in the socket, so the repaired leg doesn't bend out of place or break off the solder. Although, it looks like that board uses a flash chip rather than the old EPROMs, so it may be simpler just to replace the chip...

Let me know when you get tired of your 486SPM. I've been looking for one of those.

95% or higher pure rubbing alcohol for the batter goo, need to see a pic of said missing pin.

this is the best picture i could get without removing the chip

95% or higher pure rubbing alcohol for the batter goo

Alcohol will only help remove the stuff you can get to... any of the goo that seeped under the chips or into vias will be unaffected, and since alcohol does nothing to neutralize it, any spots you couldn't reach will continue to corrode. You need to douse the area with vinegar first, then go through with alcohol to do the final cleanup.

The broken pin on the bios is easy to fix as for some of the goo that has seeped into cracks and in the holes you can clean with some fresh solder. Once the goo starts attacking the traces and other layers of the pcb you are in trouble.

memsys wrote:

Last week i took a look at my Chaintech 486SPM LINK that i had put aside years ago due to not being able to get it working , i n […]
Show full quote

Last week i took a look at my Chaintech 486SPM LINK that i had put aside years ago due to not being able to get it working , i noticed two things.
1 there is some corrosion where the barrel battery used to be
2 there is one pin of the bios chip that is damaged and not making contact .
No wonder it did not work 😒 .

Question 1: what is the best way to neutralise and remove the battery goo? (vaguely remember vinegar but i'm not sure)

The annoying part is that the goo is also inside those 2 tiny holes.

Question 2: the damaged bios pin is missing the smaller part of the pin. what is the best way to fix it ?

*looks at time* what 3:30 (am) already

It looks like the D1 and D2 resistors are shot as well (they're cracked). You'll probably have to replace those as well.
If you don't feel like soldering on a new leg, a jumper wire would be required.

EDIT: Maybe those D1 and D2 things aren't resistors (they don't have resistor markings). Whatever they are, I'm certain they're cracked in the middle. Maybe from too much voltage?

You'll have to check the rest of the PCB for bad capacitors or resistors soldered in backwards.

The "D", and the symbol underneath them, would suggest they're Diodes. 😀

And that's how they're supposed to look:

Ok cleaned the battery goo.
However i saw some exposed traces on the underside of the board 😒 what can i use to to repair the damage to the green paint/lacquer ?

You don't need to fix it, exposed traces won't impact the running of the board.

If you're worried about the copper tarnishing (from an aesthetic perspective), you could coat it with some clear nail polish.