A500 Plus Repair

[James1095]

That doesn't look too bad at all, just scrub it with vinegar to neutralize the battery electrolyte and then rinse with alcohol or distilled water and dry thoroughly. Those capacitors are just bypass caps on the power rails to the ICs, they are probably 0.1uF (100n), anything you can find that looks similar will have a high enough voltage rating. You probably don't even need to replace it, in most cases equipment will still work with one or two of those missing depending on where they are in the circuit. Even the IC's may well be fine once you clean off the corrosion, I had one that had way more blue corrosion than that on the pins and it still tested fine after I cleaned it.

I highly recommend kynar insulated wire wrap wire for fixing damaged traces. You can form it neatly and use dabs of hot glue to hold it down when you're finished. It's what they used for fixing PCB errors in the factory back in in the days before CAD mostly eliminated them.

[James1095]

Not necessarily. You should scrub the solder mask off the discolored traces and scrub or scrape off the corrosion until you get clean copper. If the trace is not broken then it's probably ok but you should verify with a multimeter. The most vulnerable area are vias, these are tiny plated through holes used to pass the signal from one side of the board to the other. Electrolyte gets into those and rots out the plating leaving an open circuit. You'll want to remove any affected ICs to clean and inspect underneath them too. Be careful because the corrosion affects the solder and seems to raise the melting point. Unless you have a vacuum desoldering tool you might consider cutting the legs off the ICs and remove the pins one at a time, but only do this on cheap commodity chips that are easily replaced. It's easy to tear up the board and turn a small job into a big job.

[James1095]

You'll need a stripper that can handle the Kynar wire too, most regular wire strippers don't go small enough.

I forgot to mention another useful trick for getting the contaminated solder out of holes is to add some fresh solder to the joint first. Sometimes you may have to do this several times but eventually you can usually suck out the old stuff. Use a properly set temperature controlled iron to reduce the risk of lifting pads. If the through hole plating gets damaged you will have to solder the IC pins on both sides of the board so check carefully.

[James1095]

I suggest doing one thing at a time, unless the machine is dead and won't boot already. Fix the battery damage and get that cleaned up, verify it works and then do the re-cap. Others will have to suggest the cap types as I've never done it on an Amiga but I use SMD tantalum or ceramic chip capacitors to replace SMD electrolytic caps on other stuff.

[James1095]

So does it work?