Reviving dead PowerMac G4 Cube power supplies with heat
The PowerMac G4 Cube, everyone's favorite Mac, is getting on in years so it's not surprising if some of its components are starting to fail or behave unreliably. Perhaps the most widely seen problem is failing power supply units, a.k.a. PSUs.
Luckily the Cube uses an external PSU, so if you can find a replacement part it's very straight forward procedure to just plug the new one in. But before you go looking on eBay and pay top dollar for a replacement consider trying to heat up your dead power supply and plug it in again.
My procedure, which has worked over and over, is as follows:
- Pop the PSU in the owen at around 90°c (195°f) for 15 minutes
- Plug the PSU into the Cube
- Plug the PSU into the wall socket
- Attempt to boot the Cube
Warning: The PSU's outer shell is plastic so make sure to keep it far away from the heating elements to avoid melting. I take no responsibility to any damage caused by following the steps above.
My procedure is inspired by a post on the now defunct CubeOwner forum, where people recommended using hair dryers to heat up their failing power supplies.
CubeOwner – Quick fix for a dead power supply, warm it up!
The theory behind applying heat is that over time a capacitor in the PSU becomes disconnected, the heat supposedly expands the capacitor lead so that it once again makes contact. Ifixit has a guide for how to disassemble the power supply.