Post · CoreSignal social

@halfpress@mastodon.halfpress.com · 5 hours ago

The positive end of the former battery mount looks overall better than the other. There is some blue crytalline material on the legs of the close by 75LS174N IC. I'm including a photo before I fairly easily cleaned most of that off both sides of the IC with a swab and alcohol.

If this is worse than I think, then I wonder if the IC is compromised. I could remove it, test it and reinstall or replace it in a socket. Not sure if I want to do that preemptively, though.

#retrocomputing #amiga3000t

A very close microscope shot of two empty through holes that served the positive end of the now removed battery on an Amiga 3000T motherboard. The eight legs of an IC just at the top edge of the frame have little bit of blue/green crystalline corrosion on, but the board traces in the vicinity seem exceedingly normal.

Aaron Mahler

@halfpress@mastodon.halfpress.com replied · 5 hours ago

I hired a crew and a crane to move the board upstairs to my workbench.

I added some fresh solder to the three battery terminals to prime them, then used my Hakko desoldering gun to suck it all back out. The battery pretty well fell off the board under its own weight.

I cleaned the area with alcohol and got some microscope shots. The worst is on the top negative end, but the traces seem intact even if exposed. I'll try to trace them and test continuity.

More...

#retrocomputing #amiga3000t

A very tight photo taken with a microscope centered on the negative through hole of the now removed battery. The board is green with lighter green traces. The traces in the immediate vicinity of the hole are partially exposed as intermittent dashes of copper, but they appear intact at first glance.

Aaron Mahler

@halfpress@mastodon.halfpress.com replied · 5 hours ago

If this is worse than I think, then I wonder if the IC is compromised. I could remove it, test it and reinstall or replace it in a socket. Not sure if I want to do that preemptively, though.

#retrocomputing #amiga3000t

Aaron Mahler

@halfpress@mastodon.halfpress.com replied · 5 hours ago

Last battery shots for now: closeups of the positive and negative ends of the battery post-removal.

The back side of the board looks altogether better than the worst of what I shared here from the front side. There is little or no indication of issues in any traces spreading from the battery through holes.

#retrocomputing #amiga3000t

A close up shot of the positive terminal end of a blue Varta battery removed from an Amiga 3000T motherboard. The most visible concern is a rusty appearance around the perimeter of the round silver terminal area where it meets the blue outer casing. The two pins look clean.

A close up shot of the negative terminal end of a blue Varta battery removed from an Amiga 3000T motherboard. There are some small bits of blue/green corrosion near the pin tip and a light roughness to other parts of the silver terminal area, particularly where it meets the blue outer casing.

Aaron Mahler

@halfpress@mastodon.halfpress.com replied · 4 hours ago

Would definitely appreciate opinions and insights from others that have more experience than I do dealing with possible battery damage.

I can try testing continuity on traces. I could apply some solder mask and hit it with UV to cure where the little bits of copper are exposed.

I'm most curious if I need to sand or clean anything that presents more concern than I might know to have.

Lastly, I can hook it all up and just see how it works with diagnostic tests.

#retrocomputing #amiga3000t

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