Joined: 05 Feb 2016
|Posted: Fri Feb 05, 2016 10:09 am Post subject: RCA CTC210CA - Cycles on and off
|RCA CTC210A- shuts off then turns back on cycle
I have an RCA 32 in CRT TV. When it stays on, it works fine, color good, etc.
But it inermittently turns it self off and then back on after it has beend turned on. It might work for an hour or two then all of the sudden, shut down, screen go blank, then restart in about 1 second. It might do this cycle several times over a period of about 10 secs. then it will stay shut off and you have to push the power button to get it to turn on again. sometimes it will stay on, sometimes not.
Sometimes it does this cycle right at start up.
During each start up, you can hear the relay click (thunk) which I believe is the deguass relay?
I took the unit apart, took the electronics shelf out to the garage, leaving the CRT in the house, and blew it out with compressed air. It was pretty dirty. During the cleaning, I found a small silver disc about the size of a dime that had come un soldered from a couple of lead wires sticking up out of the board in the "Hot / Cold" marked side of the board. I believe this is the PTC resistor used in the deguass circuit. I soldered it back, tested with my DVM, and it showed about 5.5 ohms cold and over 120 hot after soldering. Re-installed in the board.
Put everthing back together, (did not re-silicone the HV connection). it worked for about 3 hrs that night, thought I fixed it. a few days later, it does the same thing of shutting down and restarting. I have not yet pulled it apart again to see if the solder connections came apart.
I suspect that it is a protection circuit shutting down the power, then the unit restarts.
Any help you can provide will be helpful. I am a hobbiest and can repair this with a little help finding the problem. I have basic tools, including an old O-scope. However, I dont work on TV's much but respect HV!