Brought a 21CT55 back from the ETF!

[ohohyodafarted]

Tom,
Looks like you are comitted to putting in a huge effort on this set as you are intending to re-stuff the paper caps etc. It would be a shame after all the work you are going to put into this set if your flyback took a dump.

With that in mind you can take this advice and do what you will with it. During the restoration of my CT55, my flyback took a crap. I was able to obtain a replacement due to the generosity of John Folsom who was probably the only person in the world with a NOS replacement flyback for this set. Later on after I got the new flyback up and the set was running, the HV went down again. This time it was the 30KV doorknob. I obtained a new 40KV 2000pf replacement and with some small hardware mods it replaced the original quite nicely.

Upon reflecting as to the cause of the failure of the original flyback, I came to the conclusion that the original doorknob was probably leaking and placing an extra load on the flyback. Combined with the poor ventilation of this HV cage desing, it was more than the flyback could endure. More recently, I was involved with the replacing of another one of these failure prone doorknobs in the 15" GE color set that came from Colin Wood.

I see from your photos on Flicker, that your flyback appears to have been overheated. I can see from the photos it has sagging wax and drippings.

If I were in your shoes, I would buy some insurance.

Get a new 40KV 2000PF doorknob and replace the OEM POS that is in your set presently, to insure that you have a doorknob that is not leaking.

IN addition, the HV cage on this set is very poorly ventilated. Get a small muffin fan, cut a hole in the side of the HV box and force cool that flyback.

Your flyback has already been punished enough from sitting inside what is basically an oven. Don't take a chance on killing your flyback. Almost anything else in this set can be replaced, if the flyback takes a dump you will kick yourself around the block if you did not take some prophylactic measures to safeguard it. And it could fail even if you do.

My flyback runs cool as a cucumber with the new doorknob and force cooling the HV cage with the muffin fan. Go for a fan that has a very quiet sound rating instead of a high CFM. With the volume set at a normal listening level you will not be able to hear the fan running.

Good Luck