Mac G4 Cube - Powering up issues - DC to DC board?

[TimHD]

I picked up a 450Mhz G4 Cube recently on ebay. The seller said it worked fine until recently when he plugged the power supply into the wall and heard a 'sparking' sound. Since then it hasn't powered on - he believed it was the power supply, however, even with a replacement Power Supply, the cube did not power on.

Have done the usual,  replacing battery and reseating ram etc (and replacement ext. power brick), with no luck. I understand that a green light (LED) should come on if power is coming through, but could not see that anywhere (where is it supposed to be?)

Disassembling the cube, most components look fine, the motherboard and AGP Gfx card look pristine, with no obvious issues. The exception seems to be the DC DC/VRM Board (820-1152-A) - see pics below - which has some scaling/marks where the connector is - so it seems maybe the DC board took the hit?

Any other thoughts?



 

 

[CC_333]

If you want to try replacing that part to see what happens, I think I have a spare you can try (if it works, you an keep it for the cost of postage). I'm in the US, though, but it shouldn't cost too much to ship.

c

 

[TimHD]

Link to large image. See where the connector is attached to pcb. Is this damage or normal?

https://68kmla.org/forums/index.php?/gallery/sizes/962-g4-cube-820-1152-back/large/

CC_333, thanks for the offer, have sourced one locally. Hopefully that is all it needs. 

 

[TimHD]

Have now tried replacing the DC to DC VRM board on my Cube (and tried with 2 different power supplies) but still no luck!!

Any ideas?

Should I see a green light on the motherboard somewhere?

Any help appreciated.

 

[SlateBlue]

Try resetting PMU.

https://support.apple.com/en-us/ht1939