Bad Tube or Component?

[Rocket]

Out of curiosity Is there any signs that point to one or the other?

I have only ever had a tube go bad once on my 1949 RCA Victor and I didn't even suspect it to be a tube.

I wonder in a RCA 16XL what tube is most likely to go bad

[Yamamaya42]

in any tube TV, the ones most likely to fail, Damper, HOT, High voltage Rect.

[Bill R]

suspect all 6GH8 tubes.

[Tom9589]

In series filament sets, the damper always seemed to be the first to fail.

[Electronic M]

Many hum symptoms are cap related. If the bottom of the raster rolls up the cathode lytic on the vertical output is probably bad. if the deflection is grossly off freq it is probably caps and or resistors...Possibly just an adjustment, but not often.

Worth doing if you can see all tubes in a set is to look for 'white caps' if the tube cracks and loses vacuum the getter (which is a dark blotch inside the glass usually on top) will turn chalk white.


I don't troubleshoot based on what type of part much, instead if you have something on screen or don't it will usually point you to 1-2 stages (circuits around a tube) that usually only consist of a hand full of parts to check (sometimes voltage checks in the sections will narrow it MUCH further)... Look for a block diagram of a TV set and try to understand how all the blocks add to the final output...When you know it is easy tie symptoms to the block responsible for that aspect.

[Yamamaya42]

I still remember when i was a little kid, and we had that horrid hybrid and one weekend watching cartoons, I watched at the picture on it got dimmer and dimmer, and shrank from side to side, and got all fuzzy. and I told my dad " the damper just went out, on it you need a new one" and it blew his mind that I was RIGHT!
Main reason I knew was, that I had stolen his book that he almost never used ( long since lost ) and read it over and over, and it told me exactly what was failing by the symptom I saw. it was this book. http://awfullibrarybooks.net/tv-repair/

[MadMan]

Eh, I have a tube tester so I'm kind of spoiled. :/

[reeferman]

With your set being as old as it is any tube or component can go south without warning, at the most inopportune time.

[wb2mep]

I have that book too. I got started fixing TVs in the late 1970's when most of the sets we now restore/ collect were either still in use or common trash finds. That book was pretty much my "bible". It was written for do-it-yourselfers, but went way beyond simple tube replacements, even covering color CRT replacement and purity/grayscale/convergence setups. When those sets were fairly new, that book covered most of the common failure modes. I think it still would be a great book for somebody new to vintage TV.