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Why would you measure over a coil? Resistance to GND is the one that matters.
Measure R7402 by measuring from F7040 to pin 2 on U7400, this way you ensure that there are no corroded traces.
0.015 Ohm to GND is too low. Nothing more I can say. Compare it to some working boards, but the ones I have here are 5 Ohm minimum. It would most likely be a shorted CPU as it is on 2 different busses.
hi
I think I have problems with understanding how to measure things.
I measured L7550 and L7510 in diode mode, red on ground black on coil, and got 0.013
If i measure ohm on my fluke between coil and ground i get 10.9 on L7550 and L7510
My other board, with no image; measures 10.7 on L7550 and 9.6 on L7510
Sorry if i'm stupid but i'm trying to learn this!!!
That is all ok. Running our of ideas here too. You say R7402 does look corroded, are you able to take a picture? I'm pretty sure it will be corrosion somewhere. Any history on this board?
I bought the mbp for 50$ with no other information from The seller than that it wouldn't start.
R7402 doesn't look corroded. It's the pin on U7400 that it's attached to that was corroded.