Hi everyone, I'm trying to repair a Sony PVM 2730QM monitor. The picture flickers and shakes very much and I hear a strange electric noise.
The source of the noise is the Power Supply board. I dismantled the board and through an eye inspection, there is an external burn between the C621 C682 capacitor block and the R679 resistor. I think that the resistor burned first and those on the capacitor protection are just residual.
I can easily replace these components, but I need to understand the reason of the fault, otherwise it's going to happen again. I tested D609 diode and Q606 transistor off board with multimeter and they should be ok. Any suggestion to start testing or repairing?
All the schematics attached. Thanks in advance!
Full Service Manual: https://archive.org/download/sony_PVM-2730QM_Service_Manual/PVM-2730QM_Service_Manual.pdf
The source of the noise is the Power Supply board. I dismantled the board and through an eye inspection, there is an external burn between the C621 C682 capacitor block and the R679 resistor. I think that the resistor burned first and those on the capacitor protection are just residual.
I can easily replace these components, but I need to understand the reason of the fault, otherwise it's going to happen again. I tested D609 diode and Q606 transistor off board with multimeter and they should be ok. Any suggestion to start testing or repairing?
All the schematics attached. Thanks in advance!
Full Service Manual: https://archive.org/download/sony_PVM-2730QM_Service_Manual/PVM-2730QM_Service_Manual.pdf
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