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[email protected] sevensam@udel.edu is offline
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Default Philips 27" CRT problems (model 27PT543S37A) problems - chassis L01.1U

Greetings all, new to the group.

Having some problems with my TV listed above. Minor issue that does not justify going on and buying a new TV. What it was doing was, when first turned on for the day or after a couple of hours, I would lose sound and picture, but the power LED would still be on. I had to turn the TV off and on 5-7 times for the picture and sound not to cut out.

I did a ton of research on this, and (I can provide links if needed) it seemed as though the horizontal drive circuitry was bad. There apparently was a Horizontal drive kit from Philips for the L01.1U chassis that replaced the following components (which I replaced):

1-BU4508DX (Transistor)

1-BC547 (Transistor)

1-BC557 (Transistor)

1-47m/50v (Capacitor)

1-220m/35v (Capacitor)

I also replaced the BC33725 and BC32725 transistors since there was a burn mark at these points, and further tests on a transistor tester showed they were bad. So I sealed it up a couple of days ago and I thought I was good to go. But when I went to turn on the TV this morning, same issue, but I only had to turn it off and on once, not 5-7 times before the repair. This happened twice so far today.

I checked the service manual, and the error code told me to check for black current loop protection (device TDA6107/8, and items 7330, RCB amps, and the CRT). I can provide the service manual if needed.

Now, I know how to do circuit board repair, and probe needed points if someone tells me what to test, but this is my first TV repair. Any suggestions would be welcome.

Thanks!