Resurrecting a ten-year-old Mac
Q I have a PowerMac G4 that won’t start up. I press the button on the front of the case, and it lights up for about two seconds, then dims down again. The hard drive was wiped for a clean install of OS X Leopard (it ran Jaguar before that, so it wouldn’t just update without wiping everything). It was in the attic for a while when I built my own Hackintosh, but then realised I wanted to use some of my old software (such as Virtual PC, Creative Suite CS2, Mac OS 9 and so on), which I couldn’t do on a Hackintosh running Snow Leopard. I plugged in a monitor, keyboard, mouse and power cable, and tried to power it on. The power button glowed then immediately shut off again. No startup tone, no sign of life on the monitor, the fan doesn’t spin and the computer doesn’t make more noise than a lion getting fed a giant piece of meat. How do I get it to a state where I can do a clean install of Jaguar? Jake A That’s quite some necromancy! When you press the power button, it signals the power supply to fire up the motherboard, but the CPU is held in reset mode until the motherboard receives the okay from the power supply that the voltages have stabilised. If that signal never arrives, the PowerMac won’t start. This could be because the power supply never manages to deliver stable enough voltages, or it could be that the board doesn’t recognise the Power Good signal when it arrives.
On an ancient machine like this, I’d start by checking all the connectors from the power supply to the motherboard. If they seem okay you could try replacing the PSU, and if that fails, the motherboard. But really, is it worth it? You can buy a working G4 PowerMac on eBay for under £20, or you can upgrade to something substantially better for not much more. There are G5 iMacs on eBay for under £100, for example.
Unless this is some kind of industrial archeology, classic Mac restoration project (and I’m all in favour of those), I’d suggest this Mac is beyond the point at which it makes any economic sense to try repairing.