Help needed. Nanao ms9 29 stretched image.

[arcadista]

Hello everyone, recently I have been experiencing some issues with my astro city monitor.
Picture looks good, sharp and colorful but suddenly the image gets thin and gets back to normal if I hit it slightly or shake the cabinet.

I removed the monitor and check for cold soldering, repaired a few cold solders and changed some caps but the issue remains.

Attached you can see better what I try to talk about with my limited english skills.




Chassis has no label but it is likely to be a Nanao ms9 29.




Any ideas on what to check?
Thanks in advance!

[grantspain]

it could be just bad horizontal size pot
its does not look like a b+ issue as the vertical size remains stable, it does not look like a fault in the horizontal deflection circuit or a fault with the width control circuit as the picture would go super wide

[grantspain]

note there is a horizontal sub size pot on the main chassis as well to check

[radiantsvgun]

I had a similar problem, and it was what Grant suggested, a pot going bad.

[arcadista]

Thank you very much. I will check that and post ressults.

[DaveyD]

Ive had this on an MS9 too. Also I tried to adjust it on the remote board it was REALLY jittery. Soldered in a new pot and it fixed the issue

[arcadista]

Hello people, I would like to thank everyone for your interest and suggestions.
It took me some time, but I think I finally got this monitor working fine again. I checked the pots and they were not the problem. I did another pass over spots that I thought needed more soldering and that did it in the end. The monitor has been working properly since then and It was about three weeks ago.
Hope it helps in the future to the next user with problems like this. And please excuse my english!