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Old 11-30-2021, 11:24 AM   #12
R_J
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Default Re: Panasonic TX-P50STW50 Power Supply no 5V (was clicking)

Quote:
Originally Posted by Ierwin View Post
I had unsoldered the Diode that is in parallel with R207 when i still hadnt found the failed R224 (2.2Ohm). Both seemed okay. I can not completely and 100% rule out that the Diode was reversed when i put it back. I mean I triple checked but in the end its such a tiny part and there are no readable markings on it... But Im 99% sure its correct.

C204 is a new one. Which caps are your referring to by "capacitors on the +5v line"?
If D204 is indeed backwards, that could be the problem. Can you easily remove either the resistor or the diode to check? you should be able to use your meter in diode test to find the correct direction of the diode.

The caps in the secondary 5v supply seem to be 470f/25v, one is by itself off D505 and the other three are off D501

The CS pin voltage changes at the operating frequency (65/100kHz), You can try checking the voltage with a meter but you need to be very, very careful where you measure it. Try not to probe right at the ic, one slip and it could be a disaster.

You could also try checking the feedback line to the ic, If the feedback is not working the ic will not detect the drop in voltage on the secondary (5v) and not increase the drive to compensate.

Last edited by R_J; 11-30-2021 at 11:41 AM..
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