MP 1,1-5,1 4,1 backplane replace resettable fuses?

[webbp]

Other threads have suggested that the most likely problem with my backplane is that I used a GPU which drew too much power, and fried some resettable fuses somewhere on the path the the PCIe power sockets. Is it possible to replace them? Does anyone have a photo or schematic of where they are, and/or can suggest where I could find replacements?

All other components (including PSU) are working normally with another 4,1 backplane, so I know the problem is with the backplane.

Symptoms: usually no power led, hard disks and GT120 GPU don't spin up, no boot. Occasionally, after 24 hours rest, the entire system boots normally, then powers down suddenly after a few minutes of use.

PS: I have another post about another non-working 4,1 backplane. This is a different one.

PPS: The two non-working backplanes have different problems. Maybe I can use donor parts from one to fix the other?

 

[macguru9999]

Probably easier to just buy a good 5,1.

 

[Slash-2CPU]

If they're really fuses, you can replace them with solder bridges. No more protection though.

 

[KeesMacPro]

To repair a backplane you'll need a schematic.
Without that you'll be troubleshooting blindfolded.
AFAIK there is no documentation outside Apple.

The suggestion that the resettable fuses are fried could be true, but is an assumption as good as the suggestion that any other components on the board failed.
The fuses are auto resetting, so if they are cooked, the power draw was way over the limit , and makes it likely that other components are dead or almost dead too.

If they're really fuses, you can replace them with solder bridges. No more protection though.

Exactly : no more protection.
This is the whole idea of a fuse.