If the PSU on you’re powermac g5 has gone, or you think it may have, you aren’t the only one (see macintouch forums). When I was reading around on the subject I read the failure rate is around 11%, I can’t remember the exact figure but hopefully I’ll find it again later. Luckily Apple did acknowledge the problem and has extended the warranty on the power supply, which you can claim here: Power Mac G5 Repair Extension Program for Power Supply Issues
A relatively new customer phoned us up last week in a panic, claiming his server (the powermac) had stopped working and wouldn’t even switch on. We’d recently set-up a remote backup solution for him and installed an extra internal hard drive in the powermac for local backup. I’m guessing the extra load of the hard drive took it over the edge. Needless to say he needed the server back up asap.
Phoning around we found one supplier with a spare powermac psu in stock. None of the local apple stores did and most companies sounded confused, as if I was asking a silly question. We ended up paying £150-£200 for the psu, a little on the expensive side but desperate times call for desperate measures.
I’m definitely not an expert with mac hardware and I don’t have special tools for taking apart a computer – this scared me – because everybody I spoke to or every article I read said not to change the psu yourself and to take it to a professional. My advice would probably be this too, it isn’t for the faint hearted or impatient. But if you’re up for a bit of a challenge you can’t do too much damage, read on.
Get hold of a guide to taking apart the mac, such as this one. I found a few discrepancies but it gives you a basic idea on how to remove things. To start with, remove everything. At first I tried to remove things that looked as if they would be in the way, leaving a few parts behind. Unfortunately the psu is so awkwardly positioned and large that the only way to get it out was to take out everything including the motherboard.
Having removed everything, switch over the psu and put everything back – simple. In total the changeover took about 2 hours. I used a standard toolkit but struggled with the screws for the processors because you need a very long, very thin screwdriver that will fit through the holes in the heatsink. I got by with a pear of pliers, a screwdriver bit and some brute force but it took forever.
I think as long as you keep the parts and accompanying screws separated in to the order they need to go back in the task becomes less daunting. The case on these powermacs aren’t small but then neither is the space left over. There are a lot of tightly packed components in the machine and it’s a bit of a puzzle to put back together. Good luck!
Also worth noting: When you’re finished with the broken psu most suppliers told me they’d buy it back for about £50 – worth a try.