I have RCA KCS 47/ 6T74 that the flyback make a faint tick about every 45 sec or so. I can see a wiggle in the picture when it happens. Can't see any arcing on or around the HV parts. Any sage advice?
Terry

Oh, I think there's an arc somewhere. I don't know much about the model, but what you're describing can't be good for your TV.

Make sure everything in the high voltage cage is good and clean. Then look at all of the soldered connections in the cage around the flyback. Make sure none of them have high spots or pointed edges left as the soldering device was pulled away.

You can open the cage and operate the set. You should see a blue arc every time you hear that "tick". That will give you an idea of where the trouble is and what to insulate.

The doorknob capacitor may also be the culprit. Discharge the set safely, and, remove the cap. It plugs in. Be sure of direction. If arcing stops, you've found your culprit. Before you determine that is definately bad, make sure you have all dirt cleaned off. That will also arc.The replacement cap should be rated at 500 pf 20KV.
Bill Cahill

I'm glad the doorknob cap subject came up. Some may know that I restored an RCA TC-127. I think a lot of this era's chassis were very similar so I thought it would not be off topic to elaborate on this here in this thread. A lot of folks including myself overlook this in restoration for a number of reasons. I know I left mine alone. It seems like I have read that they don't often go bad but hey, it IS a capacitor. Actually, I didnt know there was one in there. I was curious of the removable component that I saw but more thought it might be some weird resistor due to the fact that it is removable. Regardless though if the thing doesent go bad, why did they make it so easy to replace. Too bad ALL caps arent "Plug And Play"!!

Thanks to Bill for giving us a value. I wonder if that is atypical value for the old RCA's. I'm now scratching my head wondering where to get a 20 thousand volt capacitor.

http://cgi.ebay.com/high-voltage-ceramic-doorknob-capacitors-20kV-DC-500pF_W0QQitemZ250195645475QQihZ015QQcategoryZ3633 5QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

You might have a better chance of seeing the arcs if you turn the room lights off while it is arcing (and your eyes are dark-adapted after 30 seconds or so). Just keep your hands in your pockets while snooping around a powered-up, open TV chassis in the dark!

--Bob

Tnx for all of your replies! I had the cage off snooping around but didn't see any problems before I posted the question. Bill C. gets the gold star. I poped out the cap and the ticking had gone. Cleaned the cap reinstalled and the HV started making a hissing sound. Replace cap and seems to be work ok with out the ticking.
Terry