1971 25" RCA CTC-44A Chassis TV Turns Off

[joeseattle70]

I haven't been online much in a while, but some of you were helpful in the past with some previous issues. Two weeks ago, it powered down, and I hit the reset button on the back and all was well (thought I could have had a power surge). Since then, it started doing it more and more, and today it won't do anything. As soon as I hit the reset button, it dies. I have the RCA factory Field Service Guide, and it appears that it could be a couple of minor things such as the CR402, but I read it could be a short in the tube itself. The convergence board, video board and tuner have all been rebuilt in the last couple of years. Any ideas, or anyone experience similar issues? Many Thanks! Joe

[miniman82]

Ya know, I'm not one for a square screen but this one caught my eye. She's a looker sir, great picture and I hope you get it repaired!

[timmy]

dont know if this will help but maybe the breaker is bad, dirty building resistance getting hot and shutting down.

[DaveWM]

if you have a way to monitor the AC line current, I would start with that. if excessive (more than 3amps) then you know the breaker is doing what it should do. If its high, have the power supply caps been replaced, shorted caps would be 1st thing to check for excessive leakage. Another likely short would be the horz output transistor, those are under a lot of stress. You should be able to pull it out of the circuit and do a standard transistor check with a VOM or a DMM in the diode mode

[ctc17]

Is the 44 the early SCR horizontal output set?? I remember reading mag articles that talked about that issue with the SCR sets. I could find it if that's what you have

[bgadow]

Don't worry about the tube. I'm with the other guys, bad filter caps or the breaker is worn out.

[radiotvnut]

In those solid state RCA's, breaker tripping was usually caused by shorted power supply diodes, shorted/leaky horizontal deflection SCR's, or shorted/leaky power supply electrolytic capacitors. I've never seen a shorted CRT cause the circuit breaker to trip.

[ctc17]

Read this, its not the crt but it may require some troubleshooting

[joeseattle70]

Sure appreciate the advice, and for that great article, too. I've got my work cut out for me this weekend, and I'll post a reply with what I find out :-)

Joe

[zenith2134]

thanks for the scans they'll be downloaded for if/when I get one of those chassis.
good luck, joeseattle. These can be the worst kinds of problems to deal with...For example i had a matsushita quasar 13'' that kept turning off intermittently. In my case it was a bad case of poor solder from the factory..on the FBT. luckily. Annoying though since I had tested a bunch of p/s parts out of circuit first..

[Gunslinger]

I had many problems with these sets that turned out to be either the scr's or the diodes CR1 and CR2. For intermittent times, we just replaced the 4 components and problems cured. Make sure you use new heat sink paste. C6 were a problem also.

[bgadow]

I had a similiar set given to me once; beautiful cabinet. The guy had bought it new and he said the dealer never was able to get that set to be reliable; eventually he just gave up and bought something else. I think he just needed a better tech, but that sure wouldn't have been me!

[joeseattle70]

Thanks all for your advice. The high voltage curcuit has 2 bad components. Have been trying to find parts...have a good contact in Seattle for them through a very reliable tv resource. If I cannot locate them, I'll put feelers out here. Can't imagine that it would be impossible to find the parts. Where there's a will there's a way.

[Gunslinger]

what parts do you need?

[jstout66]

and don't forget Moyers.... since it's an RCA surely they would have the parts.
That's a really nice set, and from previous posts I know you went thru a bit to get it going that good. Didn't you have a new picture tube intalled in it?