hey guys, i am in the process of restoring my ctc16 roundie combo, had it since new. Ive been working on the cabinet but now I need to find someone to work on the chassis. I have a green screen and the 6gu7 tubes dont light up, or only one of them does. Is there anyone in the New York tri state area who would take a look for me, am willing to pay, i like to tinker but i am not a tech. im a tube changer only. thanks Bruce

Have you tried swapping the 6GU7 tubes around, to rule out a bad socket/tube?

yeah, i have. ive put new in, tapped on, i used to have an old guy work on it but im sure hes gone on to better things by now, they used to come up if i tapped on the bottom but no more.

... the 6gu7 tubes dont light up, or only one of them does. Is there anyone in the New York tri state area who would take a look for me, am willing to pay, i like to tinker but i am not a tech. im a tube changer only. thanks Bruce
Hey reflow solder on the two ground stakes on the far right end of the chroma board. These grounds open and kill the 6GU7 heaters. Very common ailment of the CTC-15, 16, 17 and 25 chassis. It can cause a 'cascade' of events: 6GU7 plates go 'waay positive, driving CRT grids positive (since they're direct coupled), causing CRT beam current to avalanche, which can kill the 3A3 and eventually fry the flyback if left to run unchecked. Bill(oc)

check the wiring on the chroma board.i have had this issue too many times.there are two wires that corrode or lose contact.they are on the far right side of board.good luck and if you cant find it,let me know,i will send pictures

thanks for the input guys, ill take a look at it when i get back upstate to where i have it. Im getting alittle carried away because the cabinet is really starting to come together, THANKS SAMPSON 159, and i really dont want to screw it up worse. also the board those tubes are on looks alittle brittle and if i break it , i think ill be permanantly up a creek...

Spray a SMALL amount of deoxit at the base of the tube before pulling it if it's the first time you pull one, it will make it come right out without stressing the brittle board. Those tubes get kinda stuck in there after a while and this makes them "break loose" right away. Plus, the deoxit makes a better connection when it's replaced.

This thread helped me too, I have a CTC 15 clone Philco roundie with similar issues but with the red, I'll check all those connections mentioned.

Had this happen on one of my CTC17's. The picture would bloom to a purpleish hue and then would bloom to the point of raster fade out. I noticed the 6GU7 filiments going out at this point. Reflowed solder on the chroma board grounds and viola. Problem solved. Board flexing seemes to take it's toll on those grounds.


Hey reflow solder on the two ground stakes on the far right end of the chroma board. These grounds open and kill the 6GU7 heaters. Very common ailment of the CTC-15, 16, 17 and 25 chassis. It can cause a 'cascade' of events: 6GU7 plates go 'waay positive, driving CRT grids positive (since they're direct coupled), causing CRT beam current to avalanche, which can kill the 3A3 and eventually fry the flyback if left to run unchecked. Bill(oc)

Great info to have thanks OC, I have a 17 on the back burner, I will check those out when time.

I don't know if it's the solder they originally used or just the passage of time, but bad joints are very common. The CTC-7 I just picked up had the convergence board only hanging on by 1 ground point, which was itself loose. I always reflow joints that look suspect with fresh stuff, just to make sure I have good connections.

I don't know if it's the solder they originally used or just the passage of time, but bad joints are very common. The CTC-7 I just picked up had the convergence board only hanging on by 1 ground point, which was itself loose. I always reflow joints that look suspect with fresh stuff, just to make sure I have good connections.

My CTC-10C also had ground stake problems at the PCB's. I could bump the chassis and cause the raster to go black for a moment. Poked the PCB with a pencil eraser, and found the problem. I've never had this problem again, at least on this set.

hey guys, i am in the process of restoring my ctc16 roundie combo, had it since new. Ive been working on the cabinet but now I need to find someone to work on the chassis. I have a green screen and the 6gu7 tubes dont light up, or only one of them does. Is there anyone in the New York tri state area who would take a look for me, am willing to pay, i like to tinker but i am not a tech. im a tube changer only. thanks Bruce

I live in Trenton, NJ. If you can bring the chassis to me, I'd be happy to help you.

PM me if you're interested.

...Reflowed solder on the chroma board grounds and viola. Problem solved. Board flexing seemes to take it's toll on those grounds.
Yep. Didn't take more than a coupla cycles of pulling/reinserting tubes to crack those joints originally. Reflowing with a heftier mass of solder generally solved the problem.