Sony 5-303E off-center image problem

[TechneMoira]

Hello Videokarma friends!

I'm currently restoring a Sony 5-303E portable TV. I have a very annoying problem however.

I managed to make the picture reasonably symmetrical in vertical and horizontal directions, and stable vertical deflection. However, I cannot center the image dead center on the CRT. That is, I COULD center it, but when I do the image goes all haywire and a weird screeching noise comes out of the TV (speaker ?).
Only when the image is off-center (on the right looking at the CRT front) does it remain stable. When i try to adjust the horizontal position from the right to the left to center it, first the top of the image starts to go all jagged and wavy. Then, when i try to push the image even further to the center, it goes completely bananas.

B+ is normal, current-draw is normal, no overheating parts, no sparks, picture is stable (off-center), all electrolytics have been replaced, brightness and contrast can be set normally over the whole range (0 to 100%). Possibly/probably badly aligned sound IF (good picture - no sound / no picture - good sound).

Would the problem have anything to do with the horizontal deflection oscillator? Or should i look for the cause elsewhere?


At this stage I'm a bit mystified what could cause this problem. Any idea where to look for the problem or how to diagnose it (without a scope.. .mine broke down unfortunately ) ?

Thanks
Cordially