
echo26
New User
Jan 18, 2021, 4:30 PM
Post #1 of 1
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No power, No standby voltage, low relay voltage, no power light
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i have a 2007 Sony Kpf432m91, after hearing a hiss and a. Pop, the unit never turned on again. I saw a 22uf cap and replaced it, still never got a response. I am totally confused because it has like 2 main boards for the power supply including the flyback transformer. I was going on tracing the possible fault because I did some voltage checking and the primary power supply is alive. 240 on. But when I was checking a secondary board, its outputing 4.5 volts for the relay line instead of 7, and 0 stamdby voltage. I have the schematic, service manual and owners manual. Can someone give me enlightenment. i was wondering is the standby voltage should be 0 if there is no load, such that the second board (flyback) isnt connected to the main board wimhich I'm troubleshooting. Went to see if the H.out Transistor is shorted but seems not. Not shorts or voltage drop but haven’t confirmed is b+ voltage is alive/overvoltage due to my hesitation. Any help would do.
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