Wife's small refridgerator stopped working. I tore it down just for fun. Found that these little guys do not even have a compressor. they just use heat exchange somehow with some heat sinks and fans. Anyway, I plugged it in and found that the control board was squealing like a pig. The fans would rotate about 5* every second and stop. Kind of like it kept resetting or protecting itself. You could hear the squeal stop about every second.
I removed all loads to the board and it just has a constant squeal. I think all the fans are 12V DC. I seem to remember you experienced techs mentioning that a squeal points real hard to a certain component?? I do not have any visible damage on the board and there is a 3A fuse in it that is not blown so I a little puzzled. Could this be a mosfet or does this point to too much ripple getting over to the DC buss? Just curious. I am sure someone smarter than me could trouble shoot this one in 5 min.
I checked for shorts on the twin mosfets on a heat sink and gate to drain did not show shorted but I realize that does not mean all good..
I removed all loads to the board and it just has a constant squeal. I think all the fans are 12V DC. I seem to remember you experienced techs mentioning that a squeal points real hard to a certain component?? I do not have any visible damage on the board and there is a 3A fuse in it that is not blown so I a little puzzled. Could this be a mosfet or does this point to too much ripple getting over to the DC buss? Just curious. I am sure someone smarter than me could trouble shoot this one in 5 min.
I checked for shorts on the twin mosfets on a heat sink and gate to drain did not show shorted but I realize that does not mean all good..