RCA CTC? Table top with rolling cart

[freakaftr8]

It looks significant. I dont think I've had one with wax loss that much. I had a '66 Magnavox color once that had a ton of wax loss and a burned up flyback.

I haven't found any shorts on the filters. But a shorted fly I dont believe will cause excessive wattage upon powerup immediately. I believe the Horizontal output plate cap removed should shutdown HV? Am I correct?

I'm grabbing my watt meter tomorrow.

[Yamamaya42]

Those old electrolytics have always been a weird beast, no telling how will act once they get 100v-400v on them, that's why they made those old leakage testers, may not see a short with a meter, but once they get up to voltage, they crap out.

I'm surprised my CTC-16XL did not pop breakers after sitting in storage for so long.

not sure what you mean by c2, but if it's C2 via the SAMS on my CTC-16XL , then it might be C2a, that has the highest V, right off the choke.

or you may be thinking of C1a SAMS placed C1 in the middle of the 2 :/

As far as flybacks, i think you are right, with the HOT removed, the load should be removed.


that is always the fear with mine...
Even though there is no wax seen under mine and it looks fine, I'd feel beter having a spare.

[freakaftr8]

In a turn of events, I will be replacing all the lytics in the power supply. Some of the 80 micro farad are pretty excessive. Ill be cutting off the cans and restuffing them. The reason the circuit breaker was popping is because it is apparently bad. When I wiggle it I can watch the resistance go from to 250 down to about 8ohms.

Just not worth the chance that I may stress the flyback more than it looks already by running a worn out power supply.

This tv should be fun! Haven't even got to power it up yet to see how many gremlins it has and it already under the gun..

I lifted the chassis out tonight and brought it upstairs to my workbench to start the process but too dang worn out from Taekwondo with the kiddos so I'll be ordering caps tomorrow and cutting the ol cans right off to prep.

[old_coot88]

Originally Posted by freakaftr8

The reason the circuit breaker was popping is because it is apparently bad. When I wiggle it I can watch the resistance go from to 250 down to about 8 ohms.

Are you measuring this between the circuit breaker's two contacts, or between a contact and ground?

[freakaftr8]

Between the two pins on the breaker.

[Yamamaya42]

Originally Posted by freakaftr8

It looks significant. I dont think I've had one with wax loss that much. I had a '66 Magnavox color once that had a ton of wax loss and a burned up flyback.

I haven't found any shorts on the filters. But a shorted fly I dont believe will cause excessive wattage upon powerup immediately. I believe the Horizontal output plate cap removed should shutdown HV? Am I correct?

I'm grabbing my watt meter tomorrow.

On second thought, after looking over the SAMS a bit again, removing the damper should de-energize the FBT completely, it gets is voltage via the damper through the horizontal linearity coil & L35(ctc-16 ) L36 (ctc-16xl)

So if by any chance, there is a short in the primary, removing the damper will take the load off the main bias.

[freakaftr8]

Good call. I found C136a and C136B, the 450v 80uf and the 350v 2uf on the shortest can filter bad with high ESR. The other two cans seem ok thus far. One goes to the deflection yoke, and the other is part of the RF AGC.

I'll be replacing those tonight and maybe fusing the bad circuit breaker and attempting a powerup. First I'll test the shunt reg, HV rect, and H output tubes for shorts. That fly has seem some hard use it looks.

I quickly dialed in the bad from the checkable by the old speaker test.. both C136s off the short can produced no audio.

[freakaftr8]

Well after replacing the 3 450 80uf and a 350v 2uf heres what I got.

So looks like a vertical recap and something not right about the IF stage. Blank raster.

By the way. The circuit breaker was doing its job. Was tripping at 985w!!!

[Yamamaya42]

Originally Posted by freakaftr8

Well after replacing the 3 450 80uf and a 350v 2uf heres what I got.

So looks like a vertical recap and something not right about the IF stage. Blank raster.

By the way. The circuit breaker was doing its job. Was tripping at 985w!!!

check the 150k resistor on the vert height Pot, they are almost always bad.
(the one to the 390v)


and the 180k and 150k in the IF section ( r48 / r50 on CTC-16xl ) off of bias point 3, they always go out too, they were out on mine.

[old_coot88]

Have you DeOx'ed the service switch? It can cause blank raster.

[freakaftr8]

Not yet. I'm going to check all the tubes. I'll DeOx'ed the switch too first.

[freakaftr8]

So I have most the chassis electrolytics recapped along with the white wax ELMENCO caps. Also found the usual drifted 150k off the vertical height pot.. 1 bad 6GM6 found thus far. Probably contributing to the near blank raster I was getting. Also going to replace that yellow dry 40mfd or so axial dry cap on the vertical board for good measure.

More to come.


Edit: those ELMENCO are apparently ceramic mylar according to the internet. is that true? They test good.

[freakaftr8]

Cool! A shorted 6GH8 burst amp (what's new), a bad 6KZ8 on the tuner, and a bad 6KA8 AGC, and some bad sound IF and audio output.

That explains the blank raster. Still looking over vertical board at the moment. Also going to remove the cover on the IF and have a look at those resistors.

[freakaftr8]

Off topic, my daughter's painting of the NBC living color by RCA logo she painted. Quite the artist.

She was watching me go over the chassis last night and decided to copy a portrait I have on my wall I'm my workshop area. The Joy's of children.

[freakaftr8]

Well I have the chassis power supply recapped. also changed out that 150k resistor on the vertical height pot and the 150v 50uf yellow cap on the vertical board. Still have a nasty vertical issue to deal with.