1965 zenith COLOR!

[radiotron]

Originally Posted by DaveWM

how did you determine the flyback was bad?

Well the hv cage inside was coated over black flyback wax was all bubly, and coming off, and when i replaced the horz. output tube the cabinet rattled like crazy hummed (tuned it off just in time to save the picture tube!)

[DaveWM]

did it look like this

http://videokarma.org/showpost.php?p...1&postcount=22

flyback can look bad and be ok. You should try to determine its bad before replacing.

[DaveWM]

Originally Posted by radiotron

Well the hv cage inside was coated over black flyback wax was all bubly, and coming off, and when i replaced the horz. output tube the cabinet rattled like crazy hummed (tuned it off just in time to save the picture tube!)

The normal failure mode of a flyback is smoke pouring out from it, and maybe the horz output tube red plating. Never heard of a bad one causing a cabinet to rattle nor do I understand the ref to turning it off just in time to save the picture tube. I don't see how a bad flyback could put a picture tube in harms way.

[Penthode]

The rattle could come from the power transformer if there is a short on the B+ or if there is a shorted rectifier.

Then again I have seen bad HO tubes which have a short oftem accompanied by flashing. A bad tube could perhaps put a heavy load on the B+ which causes the rattle.

What is the source of the tube? Was it tested to be good?

[radiotron]

Originally Posted by Penthode

The rattle could come from the power transformer if there is a short on the B+ or if there is a shorted rectifier.

Then again I have seen bad HO tubes which have a short oftem accompanied by flashing. A bad tube could perhaps put a heavy load on the B+ which causes the rattle.

What is the source of the tube? Was it tested to be good?

new old stock tube pulled the hv rectifier out, and it didnt do it,
also after it was on before the tv smelled like bad smoke for the whole week!
= dead king = more money to

[radiotron]

the crt got a leak the other day
but i got a good strong picture tube for it already in

[miniman82]

Originally Posted by radiotron

Well the hv cage inside was coated over black flyback wax was all bubly, and coming off, and when i replaced the horz. output tube the cabinet rattled like crazy hummed (tuned it off just in time to save the picture tube!)

It's been said to you before, but I'll say it again:


you need to read some troubleshooting books on TV repair theory, because this NOT the correct way to repair faults.


Just because a flyback melted off its wax doesn't mean it's literally cooked, and a humming sound indicates nothing more than a loose part on the chassis. Sometimes it can mean there's a dead short on the secondary of the power transformer, but I always check for that before I even variac a set. Have you checked for a drive waveform at the horizontal output tube grid yet? Have you checked cathode current? Did you go through the horizontal section setup procedure in Sams? Checked B+ voltages? Ohmed out the flyback windings?

These are just a few of the things I do when servicing a set.