Help with old G3 AIO display

[Super20]

I have an old beige G3 all-in-one that has a weird display issue. When i turn it on the screen is dark. I can fix it by going into the display config in the preferences and saving the display profile, but as soon as I restart or something, it's back to normal again. Is the video card bad or a battery dead inside or something?

 

[Makosuke]

Does the clock also reset every time it's off? That sounds a bit like a dead motheboard battery, though admittedly that's not the first symptom I'd think of if you have one.

I expect those, like most Macs, use 3.6V lithium "1/2 AA" batteries--open it up, find the battery, pull it out, and take it to Radio Shack or your local computer shop, and you should be able to buy one for $5 or so. Hopefully that'll fix your issue. If not, the battery will still die eventually, so having a replacement won't hurt.