5154 Monitor ... Another one :-/

[jammaster]

Hello!

I have tried to fix my 5154 monitor.
I have full recaped the PSU board. (all electroytic + x2 big power resistors and filter caps).
The monitor have worked 2/3 minutes with a low scale image on screen (image reducted on the the screen).
The monitor make, now, a high pitching sound providing, i presume, from the THT (?).
High voltage section dead or detune?
Heater problem on the neck board?
I haven't try much longer with power on because it scare me ^_^,
No white raster on screen :-/

Is there a service manual with all the correct voltages outputed by the PSU?

Thank a lot.

 

[KenEG]

I believe the smaller than normal picture would point to something wrong in the yolk circuits. I think if it was a high voltage issue you wouldn't get a picture at all, or maybe a very dim and fuzzy picture. If full height but not width, check the horizontal sweep. If wide enough but short, the vertical sweep.

 

[jammaster]

Now, i have nothing on screen. Just the crisp noise/sound.
It smell "ozone" on the back of the screen.
focus, brightness, high voltage variable resistor near the flyback?

 

[KenEG]

The smell of ozone indicates arcing. I would take it apart and inspect carefully looking for burn spots indicating arcing. I got a free TV years ago that I fixed by simply removing a section of a connector that was burnt and arcing because of the carbon. It sounds like you might have had dust or dirt causing a high resistance short lowering the sweep voltages that has now totally shorted out.