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Mitsubishi cs-32509 no power

The set will not turn on now after it died with a loud pop. So far I have not found the problem after replacing the flyback transformer, HOT, avalanche diode D961 and the caps on either side of it, and also replaced the regulator IC951. All diodes in the power supply circuit check ok and both fuses are ok. I have also resoldered most of the board too. I have 18v standby when plugged in and when the power on button is pushed I see voltage on the power on line comming from the opto isolator PC951. The regulator sounds like it is trying to start and only shows 5v or so on it's output pin 1, I'm guessing b+ here should be around 130v. What else can I try on this tv?

thanks for any help, Mike

Reply to
Mike Scarcella
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I just went through a long Mits CS3535R repair, and have no idea if the circuits are similar, but on mine, pressing the power on button fired a relay on a side PC board, which supplied 120V to a full wave bridge rectifier on the main deflection board. Pulling the 120V feed connector confirmed I was getting power to the main board. Then I checked input voltage to the regulator IC.

Is your input voltage to the switching regulator IC OK? There were several bad caps in this area that I replaced.

My IC input voltage was getting dragged down by the bad regulator chip. All this was done with current limiting as I was in danger of smoking components (again). After replacing the regulator IC on the primary side, of the main transformer I was still having problems on the secondary side where there were four output voltages. Removing the rectifying diodes one by one for each of the four single wave rectifying supplies let me track down which PS voltage supply circuit had problems.

"Mike Scarcella" wrote:

Reply to
T o d d P a t t i s t

I measure 330v at the input to regulator pin 3 and nothing at pin 1 output when the power on button is pushed. I may have blown the regulator again. I will try isolating the other voltages from the primary power supply but they don't seem to be related to the b+ supply in the 32' tv.

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Reply to
Mike Scarcella

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