I have a two year old 27" RCA TruFlat TV. When it is turned on, I get nothing but a black screen. When I thumb through the channels, I occasionally get sound from one that lasts for a few seconds and then "crackles" off. When this problem started intially, the set would turn itself off right after being turned on. For some reason it isn't doing that any more. I'm wondering if lightning or a power surge damaged this set and if it's worth fixing. Any ideas? Thanks.
I repaired an RCA same model with a very similar symptom. I found bad connections on the printed circuit board at L411 and L 412 (coils) in the horizontal drive circuit. Give the set a good Fonzie ( Happy Days) smack on the side and see if it comes on. LOL. Bad connections are common with that model. It is probably worth fixing and no, lightning didnt do it.
L 411 and L 412 are the coil locations as marked on the PCB. They are near the heat sink where the horizontal output transistor is mounted just behind the big transformer with the long red wire. You can also tap on the bottom side of the PCB lightly with the plastic end of your screw driver while the set is on to hone in on the sensitive area. The TV will say OUCH (that is react simultaneously with the impact) when you hit the right spot. Sometimes you can visibly see the bad connection (looks like a black ring or a crack around a solder point) Sometimes they are not visible. When in doubt solder the neighborhood where you find the most sensetive area on the PCB. Tap again to confirm that the set is solid. Meaning, no more reaction to the taps. Your fixed, put the set back together and enjoy.
You might check out some of the good Sunday sales and get yourself a Panasonic TV. I still seem to think you have bad connections and maybe missed the right one. Sometimes they are hard to catch and require several attempts. If you dont feel like saving it for a rainy day project then toss it and get on with more important things. Good luck !
Yes! Give me the resistor location printed on the CRT board and I can look up the value for you. Check for any burn signs on the resistors. The resistors will be marked with an R xxx. Based on our previous conversation, resistors are rarely intermittant. When you gave the set the Fonzie slap you said it came back on. That is indicative of bad connections and not a failed component.
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Gave it the "Fonzie" smack and just like you said, it came on! Any pointers on how to locate and fix the connections? I'm no TV repairman but I am an aircraft mechanic and I do have access to a soldering iron (bigger the blob, better the job)... Thanks for the help.
I tried re-soldering multiple connections without any luck. I still have the same problem. Some time I get a picture for a minute, mostly just sound. Sometimes it sounds like the TV is changing channels on it's own... Junk it?
I'm now told the resistor on the CRT socket is bad. Any tips on changing that? Thanks.
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