Zenith H2447R 19" Porthole TV

[Electronic M]

Before condemning the flyback verify the drive voltage at The output tube is good, AND that the oscillator frequency is correct. I've seen plenty of good flybacks make death squeals from the frequency being off...they also stop making HV when the frequency is off.

[Crist Rigott]

Originally Posted by Electronic M

Before condemning the flyback verify the drive voltage at The output tube is good, AND that the oscillator frequency is correct. I've seen plenty of good flybacks make death squeals from the frequency being off...they also stop making HV when the frequency is off.

The TV is playing like there is nothing wrong. Just that noise from the FB.

[Crist Rigott]

The freq. 15, 850. so that looks good.

[Kevin Kuehn]

Originally Posted by Crist Rigott

The TV is playing like there is nothing wrong. Just that noise from the FB.

Any chance the coil has gotten loose on the core? If it can move you could be hearing a harmonic of the fundamental frequency.

[Crist Rigott]

Originally Posted by Kevin Kuehn

Any chance the coil has gotten loose on the core? If it can move you could be hearing a harmonic of the fundamental frequency.

Good question. I checked and the coil is tight. After running the TV for several hours tonight, I felt the coil and it was barely above room temperature and the core was warm but not hot. I could grab it with my hand and hold it for a long time with no problem.
The squeal seems to have diminished some. Barely audible now. I'll check it in the morning and see what happens.