That CTC-15 Combo is Actually a CTC-16

[RCAkid]

OK, here is an update on the combo in TX.

Brought it home on Wednesday. Stereo works very well for its age and for not being restored. The turntable works as well. The tv on the other hand....

We had all hoped it was a CTC-15, but alas, it is a CTC-16AH chassis. Which is not a bad thing...it is still a roundy, just hoped it would be a bit older. The good news is that it doesn't seem to have had a ton of repair work done on it. All interlocks and screws are in place and not a bunch of junk parts inside the set or scratching of the wood base the chassis sits on. The bad news is, when it went, it may have gone out big.

Ok, brought the tv up and it looks like all I have is filament voltage, which is a good thing at least. It would seem that the low voltage power transformer is somewhat functional or at least part of it. That is the extent of the good news.

I know I need to go through the power supply and begin a recapping job and check all tubes, but here is what I also know. I suspect the flyback is cooked. It has the smell of being quite hot and while there isn't any wax drippings, there is a good bit of bulging and some cracking of the rubbery coating on the windings. While there doesn't appear to be any arching marks, it just doesn't look "right" if you know what I mean. I need to get the flyback tester out and check the windings but something big is dead in this chassis.

Additionally, the filament on the 6JE6/6LQ6 does not light. The tube is still under vacuum and the getter flashing is still in tact. I cannot detect any filament on the focus tube and the 6BK4 is not lighting either. All other tube filaments light including the CRT's. It is very apparent that there is no HV.

I do have a working CTC-16X chassis and a working CTC-21 chassis, both of which are pretty close to the CTC-16AH with the 16X obviously being closer, so I am somewhat familiar with this complicated chassis. But I have not had one in this level of failure before.

Any ideas of where to begin (aside from the power supply caps and getting the schematic) would be appreciated. Also, any ideas on where I can get a Fly for this set would be appreciated as well.

Thanks!

[bgadow]

Check the circuit breaker to make sure it is working properly. If voltage is getting past that point then something should be working. A bad filter cap would cause it to trip; I have seen breakers that were intermittent.

[RCAkid]

I always forget about those circuit breakers. You would think that as many RCA sets as I have, I would remember that. Duh.

So, the good news now is that I have audio and can tune in a channel.

So the chassis is alive at least. I still have no HV. The HO tube still does not light and I don't hear any hv frequency at all. Looks like I need to get into the power supply and begin from there. That flyback does look questionable though. Of course if a filter cap went bad and someone plugged it in, it could have fried the HV transformer and tripped the breaker. This is just speculation that further troubleshooting will diagnose. Anyway, first step, change the lytics.

Thanks for the memory jog on the breaker.

RCAkid

[wkand]

Also check the filament voltage to the Horiz Output tube. Usually it is wired with brown wire twisted together to minimize hum. I don't know what pins this would be, but they will probably be next to each other. If the tube filament does not light but there is 6 VAC to the filament pins, your fly hypothesis may be correct.

[3Guncolor]

You need to find out why the 6JE6 is not lighting. That problem should not have anything to do with the flyback being bad. Could be as simple as the tube itself. The focus tube won't light untill the flyback is running and the 6bk4 lights at the very bottom could be related to why the 6JE6 is out can't remember if it gets its filiment voltage from the same source.

Good luck

[RCAkid]

Yes, finding out about the 6JE6 is one of the first places. Hopefully it isn't a big mess under that chassis. I hope to pull it soon and get a better look at it. And, as suggested by other AKer's, it may just be a bad tube.

Since the circuit breaker was tripped, there most certainly was an overload of some sort. In my experience, albeit limited, those weren't typically known for tripping for no reason.

But at least the chassis isn't dead so that is a start. I am sure though that once HV is back, there will be the plethera of ground solder connections to deal with that is common to these chassis.

I will be checking the CRT soon. It does have really bad cataracts so I haven't worried too much about it. The set does not seem to have a lot of time on it. The stereo certainly does. The knobs tell the tale. The knobs on the stereo have the usual wear from hands turning and tuning, etc. The knobs on the TV though are still quite shiny with little or no wear on them. However, the channel display bulb in the VHF tuner is out so it has had at least enough time on it to kill that bulb. There are a couple of missing tube shields and the 6JE6 and the 6GH8A's (surprise, surprise) have been replaced, but there is little evidence to suggest the chassis has been out of the set much, if at all.

I suspect that whatever happend to it was too expensive for the owner or they got a tech thad didn't want to deal with it, they just got a new set.

Pure conjecture though. I do know that this set belonged to the gentleman's grandmother until she passed away in '99. They did used it for the stereo for a while and it is quite possible that they turned on the tv and a bad lytic fried the fly.

Who knows really. A long winded thread to be sure, but that's what I know.

RCAkid

[Chad Hauris]

As far as I can remember, the 6BK4 and CRT are on the same filament winding and this has a DC bias voltage applied to it to minimize heater to cathode voltage difference. The 6JE6 should be on the same filament winding as the rest of the other tubes.

I have a CTC-39 and the 6ME6 horiz output tube just burned out its filament from so much use. A new 6JE6C/6LQ6 fixed the problem. Have seen cases of bad sockets too so a known good tube swap plus voltage check at the socket pins should find the trouble.

I would be cautious of the diodes in the bridge rectifier here...have seen several cases of bad shorted diodes. You want to be sure it is actually operating on all 4 diodes...I'd just replace as they are so inexpensive.