Is this CTC-16F flyback a goner?

[Ralph S]

Hi: I had this CTC-16F on for about 2 hours when the HV went off and smoke started coming out of the cage. After things cooled off, I opened it up and thought I saw a small spider running out but I could be wrong. In any case if you look at the attached pictures you'll seek what look like carbon covered web-like threads on the floor and walls of the cage. What do you think is the real cause for the failure: a spider web, failed component(s) or an old flyback giving up the ghost? Is this flyback repairable?

[Ralph S]

The cage was as clean as a whistle before the failure...

[andy]

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[julianburke]

It looks like a goner.

[jstout66]

I'd call Moyers and try to get a new one. The last time I cot a CTC-16 Fly it was under $40.00. Would be easier than trying to repair that one.

[jpdylon]

I've got a spare good 16 flyback you can have for the cost of shipping.

PM me.

[roundscreen]

Originally Posted by Ralph S

Hi: I had this CTC-16F on for about 2 hours when the HV went off and smoke started coming out of the cage. After things cooled off, I opened it up and thought I saw a small spider running out but I could be wrong. In any case if you look at the attached pictures you'll seek what look like carbon covered web-like threads on the floor and walls of the cage. What do you think is the real cause for the failure: a spider web, failed component(s) or an old flyback giving up the ghost? Is this flyback repairable?

Hi Guys
I think it would be best to replace the fly back. It looks like it over heated and the tire caught fire when it started arcing. 90 % of the time it is a problem with the chassis that will cause the fly to fail so you may have to find the problem that fried your fly back before you run the new one any length of time.
One problem I found in my ctc 16 xl is someone replaced the 3ca3 with a 3a3 rectifier tube. The 3a3 caused the fly to over heat and melted down the plastic rectifier socket. I was lucky that it did not destroy the fly but I had to replace the socket. Make sure you check for this and put the correct tube in your set
This is vary important, One of the first things you should do when fixing any vintage color set is check the horizontal output current and make sure the hi voltage to the picture tube is correct. Look in the manual for your set and it should tell you the correct current and hi voltage settings. If you have to dig deeper you may also have to check the hv regulator current.
ANOTHER problem is the ac line voltage going into your set. If your line voltage is 120 ac or higher it can cause the horizontal current to go to high and the fly will start to drip wax and will cook.
When the sets where new it was rare for the ac line voltage to go over 117vac in most parts of the country.
What I do is any set made before 1965, I set the variac to 117vac and any color set made the 50's I set the variac to 115vac. Trust me, This will save you from a lot of problems that could result from high ac line voltage.
I beat the crap out of my roundies and They will play for years with out a problem once ya get all the problem out of them. The ctc 16 series chassis puts out a good clear color picture.
Good luck
Ed

[andy]

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[Ralph S]

I should point out that the set was running on a variac followed by a voltmeter and an ammeter. Just prior to the failure the voltage was 115 vac and the amps were at 2.8. From this standpoint there was nothing out of the ordinary.

On the other hand (prior to the failure) I had just changed the convergence assembly from one that was physically falling apart to one that was mechanically much better. The first one had the early selenium double diodes and the other had the newer block diodes. There may have been a parts failure on the convergence board which could have disturbed the "U" line heading back to the hor. osc. I'll have to check this. (The set ran for about 15 minutes prior to failure with the new assembly.)

Another thing: Trying to rough the newer convergence assembly into static convergence, I had the 3-dot pattern up, so the screen was mostly black. But the dots seemed larger than usual and I went to check focus. The focus control did not seem to do much.... Could this have been a symptom of pending failure?

I hopes this helps you in your sleuthing.

[kx250rider]

I think it needs to be replaced. If it were a pre-war TV, or even a 15" color set, maybe I'd try to fix the FBT. But in this case, they're available with some patience and searching. My experience is that it DOES speed up the ruin of the FBT if the TV is operated on a higher line voltage (such as by setting the "LO-NORM" line switch to "LO" when it's been in "NORM" all the set's life. Also, a fast way to destroy an RCA flyback is to set the HV adjustment any higher than it was. I leave it alone, even if the HV is measuring low.

When a new FBT is found and installed, I'd suggest checking the horizontal oscillator circuit in case it's stopped or running at a weird pulse (scope it at the plate pin of the Horizontal Oscillator tube with the horizontal output plate cap removed). A problem with the horizontal oscillator will heavy-load the output tube and burn up the FBT. If you want to do a quickie check, get a plain old neon tester and hold it next to the cap (neon tube itself; not the leads), near the cap of the H. Output tube while the set is warming up (cap installed on the H. Output). If the oscillator is working, the neon should glow as soon as the tubes warm up, and comfortably before any damage would happen to the FBT. If it doesn't light, your oscillator isn't running, or there's something loading down the horizontal output.

Charles

[roundscreen]

Originally Posted by Ralph S

I should point out that the set was running on a variac followed by a voltmeter and an ammeter. Just prior to the failure the voltage was 115 vac and the amps were at 2.8. From this standpoint there was nothing out of the ordinary.

On the other hand (prior to the failure) I had just changed the convergence assembly from one that was physically falling apart to one that was mechanically much better. The first one had the early selenium double diodes and the other had the newer block diodes. There may have been a parts failure on the convergence board which could have disturbed the "U" line heading back to the hor. osc. I'll have to check this. (The set ran for about 15 minutes prior to failure with the new assembly.)

Another thing: Trying to rough the newer convergence assembly into static convergence, I had the 3-dot pattern up, so the screen was mostly black. But the dots seemed larger than usual and I went to check focus. The focus control did not seem to do much.... Could this have been a symptom of pending failure?

I hopes this helps you in your sleuthing.

If the new convergence assembly is from another ctc16 chassis there should not be a problem. If you took it out of a different chassis # then it might cause a problem with the flyback. If the convergence panel is not from a ctc 16 chassis, Put the old one back in. Fix it with the parts from the new one if they are the same value or part #.
Magnavox chassis where known to cause a flyback failure when something went wrong with the focus circuit so that could be what went wrong with your ctc 16 even tho it is a rca.
Watching the total current consumption of the set is a really good idea but if the horizontal output current is high it may not show up as a problem when watching the total current consumption of your set. { If my writing makes sense to you} The best thing to do is check the horizontal output tube current.
The lowest current current reading I get with my ctc16 is between 200 and 202 ma with the ac line voltage set at 117v ac. If you have a sams for your set just look for miscellaneous adjustments and it will tell you how to do it. It is cool watching the horizontal output current. You get to see what is going on when the ac line voltage changes and when you turn the set on.
To be honest, It could be anything in the power supply, Horizontal osc,Output,High voltage, Focus and convergence circuits that caused the problem. OR the dam fly just took a dump.
Put your new flyback in when you get it and start from scratch.
Have a good weekend
Ed

[yagosaga]

Remove the LOPT and cook it in wax with 130° C for 20 minutes. And then, it will be OK again. See

http://audiokarma.org/forums/attachm...3&d=1227519049

Eckhard

[andy]

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