1991 Zenith Console SJ2722lk5 totally dead

[JohnCT]

Originally Posted by old_tv_nut

Thanks for the later info!

Did the separate HV supply run at H rate, or entirely independently?

The HV supply typically ran at the lower horiz rate and didn't change. Some used a dedicated osc/drive IC like a SMPS would, others would take use the horiz drive from the Jungle IC to drive the High Voltage output transistor.

The sweep rate of course would switch as the HD source was selected.

On many of these, lack of video muting would show a weird horiz line show on the CRT when switching between a standard def and high def source.

John

[TvGuru87]

Originally Posted by old_tv_nut

"almost certainly caused by horizontal sweep failure. This can occur in solid state televisions (b&w or color) because the horizontal sweep in SS sets has nothing (or very little) to do with the HV plant."

You mean caused by vertical sweep failure.

Also, the high voltage production is very much dependent on horizontal sweep working, even in SS sets.

Alright so i replaced an open 1 ohm resistor coming off the flyback that feeds 24 volts to the vertical ic and got the set partially working, but the horizontal is out of sync.