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My samsung side by side model RSG257AARS stopped cooling on both sides. Gave me several codes upon entering diagnostic mode. A sensor, a fan motor (even though both fan motors were operational upon inspection) and P<->M communication error. I tested voltage at CN79 and only had 1.89 V DC across the compressor signal pins instead of the 2.5 V DC specified. I also only had 10 V DC across CN76-5 instead of 13 V DC specified. I’m used to working on a little more simple units and just needing some help diagnosing. Are these readings off of spec enough to call this a bad pcb?
Hi @nflessner, Looking at the voltage values you posted they’re down 26% and 23% respectively and this usually is enough for electronics not to work correctly. Don’t know the model but it would help if you could somehow measure the DC power on the input side of the pcb to know if the power regulators on the board are OK (assuming that there isn’t a separate power board) and that they’re supplying the correct DC voltage i.e. the ones that convert the AC input supply to the DC required by the pcb for it to function etc. Perhaps post a close up of the board as there may be something seen that doesn’t look quite right e.g. heat stressed components or bulging or leaky capacitors etc. Here’s how to do this on Ifixit Adding images to an existing question
