Proscan PSVR80 power supply

Hi - At this point it's pretty much dead, no display or motor function. When in it's death throes, I could press a button on the control panel, it would begin the function (eject, FF, RW etc) the display would blink out WHILE it was operating, then when the operation completed, it wouldn't respond to any key presses any more. If I pulled the plug for a while, then plugged back in and left it alone, the display would work for a random amount of time before blinking out.

I took out the power supply section and was probing the pins that fed everything - I came across a pin that was fluctuating between 6 and 8 volts. I followed the traces on the PCB to a patch of poorly cleaned flux and thought maybe it was allowing voltage to leak. I cleaned the flux and tested the pin again - it was hovering steady at 0.2 volts. I hooked it back into the VCR - still dead. My conclusion is that there is supposed to be voltage on that pin, but I need schematics to be sure. I guess eventually I will break down and buy a Sams copy but at this point the cost is not worth it, so I thought I would through out the question and see what happens.

The most likely culprit, generically speaking, is bad electrolytic caps in the power supply. Mainly but not limited to the secondary circuit. Anywhere from 10 to 1000 uF or so, there could be up to about ten of them. They should be replaced with low impedance 105 degree types - lesser quality ones may run for a while, then blow the thing up - learned that one the hard way. Switchmode type supplies are pretty critical about that sort of thing.

Mark Z.

Thanks for the reply, I'll give that a look. Here's when I wish I had an ESR tester...

Scott