04 July 2022
Recently I wanted to reapply thermal paste to the CPU on my Power Mac G4 Quicksilver. This is a relatively simple task and only involves removing the CPU fan and heat sink. Before doing this I unplugged the machine and made sure I was wearing an anti-static wrist strap to prevent any electrostatic discharge (ESD) damage. I reapplied a small amount of thermal paste, put everything back together and powered on the computer. It turned on but there was no boot chime and nothing displayed on the screen. The power LED indicator faded off as soon as it was powered on, then it briefly lit up again if I pressed the power button.
I removed all devices from the computer (video cards, drives etc.) and it still wouldn't boot. I removed all of the RAM and turned the computer on again expecting to hear the beeping tone indicating no memory present/RAM issues. I didn't hear this which led me to believe there was an issue with the CPU since the machine wasn't making it to the boot diagnostics.
I installed a replacement logic board into the Quicksilver and got the same results which narrowed it down to the CPU even more. After removing the CPU and closely inspecting it I noticed a tiny amount of discoloration on several of the CPU pins. It looked like they had oxidised slightly which was strange considering it wouldn't have been removed since the machine was bought. Next I got a toothbrush and very carefully brushed the affected pins. I couldn't remove all of it but I thought I'd put the CPU back to see if it made a difference.
After reinstalling the CPU the Quicksilver chimed and booted as normal! For now it's working fine but I need to find a way of removing the oxidisation without damaging the CPU.