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Old 06-10-2017, 08:14 PM
uncleputz uncleputz is offline
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RCA model 55G55R120Q quit suddenly

This is the newest TV we own, built in February 2015. We were watching basketball the other evening when the screen went dark and in about ten seconds we lost the audio as well. The only thing that still works is the red standby light. This thing may have had one of the nicest pictures I have ever seen, and certainly the best I've ever owned. I have been searching online for information, but it sure seems scarce. What I suspect is that the logic board is kaput, but I sure would not swear to that. From what I have learned, if the standby light is on, the power supply board is under less suspicion. I pulled the back off and tested power at the power board like was suggested. I should have 5 volts on the standby terminals, and have 4.93 volts. Is this voltage low enough to cause a problem? Also, how do I determine if the logic board is working properly? My thinking is that if the logic board (mother board) was working, I should have audio even if the video was dead. Some RCA models are alleged to have bad LED strips, so this needs to be investigated as well. Like many of you, I'm basically a tube man and solid state stuff is news to me. I really don't want to junk a TV that is less than two years old to me. And, this gives me the opportunity to learn something. Do you know of a source for diagnostic information and/or assistance? Is service information available for this set? Thanks in advance for any advice or help with this.

BTW, I did not see any bulging caps or anything else that raised a red flag, for what that is worth.

Last edited by uncleputz; 06-10-2017 at 08:25 PM.
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Old 06-24-2017, 06:03 AM
tubetwister tubetwister is offline
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Bulging CAP in RCA TV

RCA TV

Bulging cap only shows it's bulged and probably bad like any CAP bulge or not , maybe more problems beyond that ,you Need DC rail voltage reads and or board (s) diag.

Indications are the power LD board and unlikely mainboard or logic .

https://www.youtube.com/watch?v=mUvclBfaMXg

Be glad you aren't in a ~ 22 vacuum tube lethal voltage delta gun color CRT roundie ,if you know ,you know ☻

LCD TV DC volts are at DC connectors pinouts > PSU /LD and logic are indicated + *very unlikely main board and or mayne Panel LED

RCA is NOT RCA corp. by any stretch of imagination ,only disposable Pacific rim rubbish now.kind of like Vizio pfffftttt They don't make TV either (RCA) probably if working not bad for that stuff.

Can't get new RCA disposable TV parts

If it matters I have formal electronics education and long ago TV bench work as we can see ,but I keep up . LCD is a walk in the park to diag. and fix but rarely worth it to fix ouside of harvested, used or cheap boards or LED bars and often cost prohibitive in any case in a TV shop or outside tech .

OTOH put your pickers to or near the wong place in and irritate the che` an old NTSC color roundie or later scan line CRT TV I like I started on way back in my electronics day and they may kill or just fry you too he he you gonna schooled about electrocution in the *HARD way you never seen outside the chair, interstate electrical grid ,Sony Trinitron 50 KV or 10-15a 100KV Iridium spark plug automobile coil that all may change your life if you still alive and they may kill or just deep fry your pickers but it usually didn't that I know ,that just gave you something you won't forget soon,

Mean and average LCD TV & panel MTBF is rubbish but it can make a terrific picture on some of them like my new active edge dimming 4K HDR 1000 Samsung UN 55 KS 8000 in here on wall with my 30+ Lb Sony ES 7.1 HT AVR .

Good luck with the TV .......shop jimmy.com or ebay has affordable usually cheap $ to buy RCA boards, but yours (maybe )

Last edited by tubetwister; 06-25-2017 at 01:50 AM. Reason: revise
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  #3  
Old 06-25-2017, 05:22 PM
uncleputz uncleputz is offline
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After lots of YouTube vid viewing and more general tinkering, I have come up with a tentative diagnosis. Much of what I found reflects your most appreciated comments. I did the flashlight trick and found I had video. I do not know about audio, since the speakers for this set are on the back rather than the TV chassis. I also do not have a VCR hooked up, so the jury is out on audio, but I have no reason to doubt that I have audio. I have start-up voltage from the main board to the PS board. I have 12 volts from the PS board to the main board when the set is turned on. I still have the standby light, and it goes out when I turn the set on. This set has never had a blue light or a green light to tell when it is on like most sets do. I do not have power from the PS board to the back lights. I disconnected the PS board from the main board, still no backlights. I have physically checked the voltage at the PS to the back lights. Both with the lights plugged in to the board, and with them disconnected. No voltage either way. I don't really know what I should have, but the best I can find out is 100 volts DC. Nothing is not adequate. So, I'm thinking my problem is in the PS board. For some reason, it appears I have lost power to the backlights. Why, I have no idea at this point. I have no reason to suspect a bad LED panel at this point. The set was working great, then suddenly the screen when dark. My wife says the audio worked until she shut the set down, maybe 30 seconds after the screen went dark. Thank you for your input and I'll be sure to get back with you after I put a PS board in and go from there.
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