@ jacadcaps - I had a PowerBook (A1138) GPU fail, having put it away all working OK, and the next time I got a screen very similar to what muffie has shown in the linked photo. It wasn't the screen cable in my situation, so I ended up getting another machine, same model, and swapping over the registration to the replacement PowerBook.

These systems are getting more flaky it seems, so I keep a few spares close by, for just such an eventuality.

The replaceable GFX cards in the PowerMacs make them worthwhile for that reason, but they certainly can use a lot of electricity to power them. Though I like my A1145 iMac as it has most of the hardware built-in, a G5, and a monitor you can now basically just switch off when you're not actively using it for a while, but don't want to switch it off entirely.

@ muffie - all you need to open a PowerBook is one of the small screwdriver sets with small torx, hex and philips head screwdrivers. They usually come in a small oblong plastic case with a pair of tweezers and the head of the screwdriver handle is usually magnetic, and I found that the hexagonal bit holder is just the correct size to remove the large pillar nut on the DC-In board of most PowerBooks, as well as the speaker/microphone securing nut, adjacent to the DC-In board.

Though you might need to file down or grind the top edge to get it to fit inside the small aperture of the speaker nut section. The bits are usually hexagonal, and those sets are usually very cheap, but just what you need to open a PowerBook with little effort.

Watch some videos, such as the ones on the PowerbookMedic website, or some other ones on YouTube to find how to disassemble your model without breaking anything, and without forgetting to remove ALL the screws, as some are tucked away in unexpected places, such as the battery and RAM compartments.