Power button problem with G4

[protocol7]

I just picked up another Gigabit Ethernet. Unlike my last rescue, this one was complete internally. It didn't chime at first, so I took out the RAM sticks and put in a pair from my other GE. It fired up fine after this (the two sticks installed were PC133R ECC, maybe not the correct kind).

While it's now working "fine", the power button is not. It won't power the Mac up or down and lights up as soon as there is power from the socket. I tried a PMU reset, but that didn't fix it. Luckily it came with a Apple USB Keyboard with it's own power button so I use that to start it up. But I'd like to sort out this power button if possible.

 

[mcdermd]

If you weren't able to boot from the keyboard switch, I was going to suggest checking the PRAM battery. If it boots fine when the battery is pulled out, you need a new one. With it booting from the keyboard, it may in fact be the switch.

 

[protocol7]

I took the battery out and it behaves the same. Pressing the case power button won't startup or shutdown. The button just sits there fully-lit. Seems a strange thing to break, but maybe that's what's happened alright.

 

[theos911]

The analog boards can go bad. Is the button actually clicking and making contact? If not, it needs cleaned or is broke. If it is, try replacing the analog board. (Analog board might not be the right name, but it is what I've always heard the little switch board refereed to as.)

 

[protocol7]

I have yet another GE here that I got in fairly stripped-down condition (three out of the four G4s I managed to find are all GE's!). So I swapped out it's "front panel board" (thank you service manual) and it's working fine. So I guess the original one has gone bad. I'll take a closer look at it at some stage and see what the problem might be. This is what the faulty one looks like (it's a different model from the one I replaced it with).

 

[theos911]

Awesome to hear it works. I don't think the a boards would be too different. Only needs to power an LED and ground an ADB line.