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New member Username: HaithemPost Number: 1 Registered: Jan-07 | Hello! I just replaced the FLYBACK transformer on my 56' RCA rear projection TV model P52921 (Flyback part # 239111, Chassis CTC195M). The HOT was not replaced and I believe the new FLYBACK is not an original part. Anyhow, after replacement the TV powered up and initially the picture looked fine. However, everytime the unit is powered up there is a hissing noise coming from the back that lasted for 3-4 seconds then it disappears. The TV worked well with the exception of the noise and a slight blurr at the very right edge of the screen. The TV worked in that manner for about 7 days until today it did not power up as it did before replacing the FLYBACK. Without any testing and with those two clues (the noise and picture blurr) can someone help me understand what might the problem be? It could be anyone of these: The new FLYBACK, the HOT blew, Driver and HOT base circuit components, the LV regulator, or maybe bad soldering to the new FLYBACK. Any good ideas? Thanks |
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Silver Member Username: Stevestar99Dahlonega, GA Post Number: 106 Registered: Nov-06 | You more than likely didn't get the HV lead properly seated into the FLY socket. It's extremely hard to keep the stripped tip end of the HV lead straight as you insert into long socket. There is a wire nut type fitting at the bottom of the socket that the lead has to go into. Pull the lead back out and if it's bent over, you didn't get it in the tiny hold at the bottom of the socket. It's best to have the strip end not longer than 3/16 of an inch, so it will stay straight and not bend over. |
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New member Username: HaithemPost Number: 2 Registered: Jan-07 | Thanks for the tip!!! There are two red wires coming out the FLYBACK. I pulled out the larger one (in diameter). It was hard to pull out and was not bent which may indicate that it was properly seated. I looked at the strip end it was about 3/16 of an inch maybe shorter. I also checked the FLYBACK soldering in the back looks fine. This hissing noise can not be possibly coming from the LV? right now the TV is not powing on at all. I am starting to suspect the HOT? Should I replace it? What else should I try? Thank you very much for the help! |
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New member Username: HaithemPost Number: 3 Registered: Jan-07 | I was able to narrow down the problem, just need a couple of information. I need to know both the location numbers and part numbers for those two HOTs (the horizontal output transistor and transformer). If you can provide me with this information I will be very thankful! |
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Silver Member Username: Stevestar99Dahlonega, GA Post Number: 110 Registered: Nov-06 | The location # is printed on the bottom of the board. You've got fly # 239111. Good source for RCA info is www.vancebaldwin.com Do a search by model # / chassis # . Also do a web search on the RCA 239111, I'm thinking that's the fly that was defective which came from RCA as a replace. If it is, don't buy the original. They explode only after a couple of hours. Vance Baldwin (RCA rep) won't sell the original, buy their replacement. |
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New member Username: HaithemPost Number: 4 Registered: Jan-07 | Thanks steve but I already have replaced the FLYBACK part 239111, I need the part number for the horizontal output transistor and transformer. Thanks! |
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Silver Member Username: Stevestar99Dahlonega, GA Post Number: 111 Registered: Nov-06 | Flyback is slang for Horizontal Output Transformer. They're the same thing. Use Vance Baldwin for parts info. |
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New member Username: HaithemPost Number: 5 Registered: Jan-07 | Thanks Steve! I checked Vance Baldwin for parts but there selection is limited is there another database that is inclusive to all the component in my RCA TV model? Thanks again |
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Silver Member Username: Stevestar99Dahlonega, GA Post Number: 114 Registered: Nov-06 | You need to buy the service manual. It's got voltage and signal readings on the schematic. The RCA manual has everything you want to know and more. $30? from Vance. You can get a cheaper version from Servicemanuals.net, I don't know if it's as complete as the RCA manual. |
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New member Username: HaithemPost Number: 6 Registered: Jan-07 | ok I will try that. How about my chassis number? I have PTK195MB on the outside cover next to the model number and serial number. However, on the main (power supply) board I have CTC195M. Can you explain this discrepancy and if it is a mistake? Thanks Steve! |
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Silver Member Username: Stevestar99Dahlonega, GA Post Number: 115 Registered: Nov-06 | ptk195mb is the model #. ctc195m is the chassis # |
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New member Username: HaithemPost Number: 7 Registered: Jan-07 | Ok i see, would you expect a high voltage leak and hissing noise if I cut and reconnected the wire to the CRT on the replacement FLYBACK ? I used metal connectors to do that. If that is the case then how can I get the wire out from either side (the FLYBACK side or the side going to CRT?) I tried gentely pulling it out and it never did. |
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Silver Member Username: Stevestar99Dahlonega, GA Post Number: 116 Registered: Nov-06 | Too late now. Yes, hissing is HV leaking. Your best bet is trying to insulate the leak. Make the splice as small as you can. Slip some kind of plastic tube over the leads before you splice. Fill the tube with silicone. Center the lead in the tube. You'll need a finger size silicone tube over the splice. WAIT 24hrs! for the silicone to completely dry. HV will blow right past un-cured silicone. If it leaks, start all over again. |
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New member Username: HaithemPost Number: 8 Registered: Jan-07 | That is a really good idea what you described. Tell me what do you think about soldering the two ends together and then use the silicon that you referred to? So how was I suppose to do it anyways if the lead at the CRT end is not and will not come out? |