Here’s a peek at what damage those little power cells can wreak on poor unsuspecting motherboards. It just happened to be an LC 475 as well, didn’t it? Not mine thankfully! :P

This Macintosh has suffered some nasty damage from an old lithium battery. The corrosion has travelled quite a distance across the motherboard, reaching connectors and several surrounding components. Have a look at the state of those ports!

The battery in this machine was a red Maxell, a brand I’ve encountered in a few older computers. I’ve seen other types of batteries cause trouble too, but this is a particularly ugly example of what can happen when one leaks.

A couple of electrolytic capacitors nearby also look suspicious. The 100 uF components have residue around their connections, while some of the other solder joints still look nice and shiny. As if one source of corrosion wasn’t enough!

Interestingly, this LC 475 has a TDK power supply with the white switch at the rear. It’s a slightly different arrangement from some of the other machines I’ve been working on, although I’m much more interested in the motherboard damage today.

Apple specified a 3.6 V lithium PRAM battery for the LC 475. On a machine that’s been sitting in storage for years, it’s worth checking the backup battery rather than leaving an ancient cell on the motherboard indefinitely. If it needs removing, the battery should be handled and disposed of properly.

Thankfully this wasn’t my Macintosh, but seeing how far the corrosion has spread makes me want to check every old computer I’ve got sitting around here. That’s a remarkable amount of damage from one little battery.

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