I was just given a G4 MDD which "stopped working suddenly".
When removing the PRAM battery I had the feeling it actually was in the wrong polarity, but I'm not entirely sure.
Fans spin, the power LED lights up, but that's it.
I've tried:
- reseating the RAM, the CPU…
- disconnecting unessential things (I noticed the optical drives IDE cable had wires cut).
- resetting PMU.
One very odd thing is, when I remove all the RAM, it does give a single beep, telling it doesn't find it. But when I put it back in, and I tried many combinations, it just sits here, not doing any sound.
I noticed the thermal paste was quite tried off, maybe one of the CPUs partially burnt and fails to execute code. I don't have spare a CPU board to try at the moment though.
Also, the logic board has some wires and SMD transistors soldered on, apparently to control one of the fans, and it also has two large resistors bridging some pins on the power supply connector on the bottom side, probably to force some load on the power supply… Some photos on twitter.
Anything I could try?
When removing the PRAM battery I had the feeling it actually was in the wrong polarity, but I'm not entirely sure.
Fans spin, the power LED lights up, but that's it.
I've tried:
- reseating the RAM, the CPU…
- disconnecting unessential things (I noticed the optical drives IDE cable had wires cut).
- resetting PMU.
One very odd thing is, when I remove all the RAM, it does give a single beep, telling it doesn't find it. But when I put it back in, and I tried many combinations, it just sits here, not doing any sound.
I noticed the thermal paste was quite tried off, maybe one of the CPUs partially burnt and fails to execute code. I don't have spare a CPU board to try at the moment though.
Also, the logic board has some wires and SMD transistors soldered on, apparently to control one of the fans, and it also has two large resistors bridging some pins on the power supply connector on the bottom side, probably to force some load on the power supply… Some photos on twitter.
Anything I could try?