I learnt from internet that this monitor model has had a load of problems with blacking out display etc. This one had similar things and I thought I would take it apart to see if it has bad caps or something. Taking the display apart made it work, the picture quality is great and it seems to be stable for long periods of time.
Freeze spray doesn't seem to do anything (main board, T-con board or PSU). Also pressing and knocking boards (main board, psu board and T-Con) with insulated screwdriver does nothing. Both of these tests were to find bad joints or components.
Measuring PSU outputs gave me 11.45V on the 12V line, it seems to be stable, adjusting backlight doesn't affect it. 5V line was 5.05V (just with a cheap multimeter)
Knocking away more, backplate over the T-con started giving me some fails, took it away and knocked the board without issues appearing. Then touching the screen with freeze spray can gave the problem and I found it is 100% repeatable.
I've got non grounded outlets all over the house. I can only get picture to the monitor from one of my computers, and I think this problem has something to do with floating voltage by SMPS because there is (depending on computer) 60 to 90V ac floating voltage.
Any ideas where to tackle this?
Youtube link to video of the problem:
https://youtu.be/ZPUvxc2OzzUPictures of the boards:
https://www.dropbox.com/sh/3a1u1gvj1asgz8g/AADWVxGQ-zrZAUceJuOR5ykra?dl=0Thank you for your inputs
-Muikku