68kMLA Classic Interface
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| My power mac G4 won't turn on after replacing the logic board. | |
| Posted by: mcmcjohn on 2025-01-16 05:32:03 Hello, I recently replaced the logic board of my Power Mac G4, but it won't even power on. The original model I was using was an AGP G4 with a 400MHz CPU. Since the board was faulty, I decided to purchase a logic board for the Gigabit model, considering a future CPU upgrade. The original system also had a 400MHz 7400 CPU, and I knew that some Gigabit models also came with a 400MHz 7400 CPU. So as soon as the board arrived, I installed the CPU and pressed the power button, but the system didn’t power on at all. I also checked the power supply and confirmed that, aside from the two pins for the 28V Apple Display, the pin layout was the same. Since the 28V wasn’t needed, I connected the original 20-pin power supply, leaving the two end pins on the board unused. Could this issue be due to the CPU patch, like MAXPower, not being applied, which prevents the system from powering on? Or do I need to replace the power supply with a 22-pin one specifically for this logic board? Here is a photo of how I connected the power supply below.  | |
Posted by: DarthNvader on 2025-01-16 06:34:33
How to use ATX power supply in Gigabit/Digital AudioStep by step instructions for using an ATX 24-pin power supply in a Gigabit Ethernet/Digital Audio Powermac G4 (one way to do it anyway): First, know that to boot the G4s up, you MUST have at least +12V of power going to the G4's pin #22 spot (white wire) even with the computer turned off...
forums.macrumors.com
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Posted by: mcmcjohn on 2025-01-16 18:01:37
Oh, I didn't know that. Thank you so much!!!!! | |
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