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No picture but sound on RCA P46820BL Projection TV

 
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Cippy44



Joined: 20 Jan 2009
Posts: 4

PostPosted: Tue Jan 20, 2009 2:39 pm    Post subject: No picture but sound on RCA P46820BL Projection TV Reply with quote

For the last couple years about once a year my RCA 46" projection TV loses picture but sound works ok. If I unplug the unit for a few weeks and then plug it back in, it seems to work ok for about a year and then it loses picture again. This third time around it's not coming back. When I turn the unit on it sounds like it's trying to power up but it's not enough to put a picture on screen.

I suspect it was low line voltage that caused this issue but am not sure where to begin looking.

It's a RCA model P46820BL.

Any ideas?

Thank you.

Chris
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minnie



Joined: 18 Aug 2005
Posts: 2877
Location: Hell

PostPosted: Wed Jan 21, 2009 10:21 pm    Post subject: Reply with quote

Are the tubes lit?
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Cippy44



Joined: 20 Jan 2009
Posts: 4

PostPosted: Thu Jan 22, 2009 1:03 pm    Post subject: No picture but sound on RCA P46820BL Projection TV Reply with quote

Tubes are lit.

I noticed a small burn mark on the main circuit board near a set of 3 jumpers..It looks like jumpers J12121, J12122?, J12123?. I'll take a closer look tonight it was hard to read the numbers.

Thanks.
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Cippy44



Joined: 20 Jan 2009
Posts: 4

PostPosted: Fri Jan 23, 2009 1:39 am    Post subject: Reply with quote

The burn mark is by JW12127 and JW12128 on the main circuit board.

I also just remembered that the sound doesn't work on my TV. I've been using a surround sound receiver and speakers for so long I forgot that the sound in the TV is not working either.

I just tried powering it up again and still nothing. When I unplug the unit I notice a bright horizontal line across the middle of the set but this only happens when I unplug it.
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Cippy44



Joined: 20 Jan 2009
Posts: 4

PostPosted: Fri Jan 23, 2009 7:36 pm    Post subject: Reply with quote

I did some more investigating this am and just noticed there is a low volume hissing sound coming from either the power supply or possibly the high voltage transformer which is right next to the supply on the main circuit board.

So now I'm wondering if the HV transformer should just be replaced?
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minnie



Joined: 18 Aug 2005
Posts: 2877
Location: Hell

PostPosted: Sat Jan 24, 2009 12:11 am    Post subject: Reply with quote

Flybacks/splitters are a common failure in RCA's.
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