Corrosion between board layers - Nan Tan FMA3300A.

[JamieDoesStuff]

Today I opened up my Nan Tan FMA3300A to attempt to fix the damage from my attempted recapping of the DC-DC board (ripped pads, capacitor put in backwards, dumb mistakes overall) from ~6 months ago. I've learned a lot since and can actually solder decently now (still doesn't start, TI TL494 + resistor are shot from that capacitor I believe)

I've removed the NiCd battery a while ago, but the corrosion is now back, and it's worse. My only conclusion is that it's gotten so deep into the ground plane and is now attacking the other internal layers of the board as well.

What could I do to prevent further damage? I've been thinking of bathing half of the board in vinegar, however that would most likely bring even more trouble to the table.

 

[GiGaBiTe]

If the electrolyte is in the inner layers of the board, there's not much that can be done. Even if you could somehow get vinegar inside the board, the only thing you succeeded doing is replacing a base with an acid that you then can't get rid of, which will further damage whatever copper is left.

The only thing left is destructive invasive surgery with a dremel and the patience of a saint. You'll have to grind down the layers of the board and chase after the corrosion. You'll have to take highly detailed photos of the areas you destroy to rebuild if you ever get all of the corrosion out. Since there are no schematics, your chances of success are going to be very low.

It'd be time better spent looking for the unicorn of a replacement logic board, or figuring a way to rig up something else to go in the laptop and use the existing screen, or a screen that would fit the bezel. Restuffing old laptops is becoming more common as they die and aren't repairable.

 

[JamieDoesStuff]

Even if I do find a replacement board, it'll have the same battery, and as such the same amount of damage done to it, if not worse. I'll fix the DC-DC board and use the machine as-is until it finally dies. Or maybe I'll go the SBC route, keeping the whole case, keyboard (should be PS/2 or AT internally), display and maybe even floppy drive and use it as a "modern" Linux machine. That'd be quite the project!