My trinitron ultrascan P990 started to act up recently. It lost its focus and about an hour later I heard a click, a static discharge of somesort and the focus came back to normal. A friend of mine suggested that it was dust causing HV leakage. I opend it up to clean it around the CRT socket like he suggested and there was not a speck of dust. From there I moved down to the flyback and cleaned the HV parts down there. Still there wasnt more than a thin layer of surface dust that whiped off with a kleanex. The big problem is that while I was cleaning I bumped and broke what appears to be a trimmer pot or cap, Its right next to the flyback on the side closest the exterior of the monitor casing. It is a blue trimmer with some sort of cover. Im not sure if the translucent cover is part of it or removable as mine is broken. It was also glued down to the board. I powerd the monitor regardless (always taking chances ;p) It powered fine, but the image is streched out majorly. Right now in order to display a 1600x1200 resolution I have the horizontal size set to 25 and the vertical size set to 30. Its is almos a 30 decimal place differance from what it was set to before. The monitor now has blurry patches in its display. Because of this I belive that the trimmer is to adjust the voltage applied to the flyback. If somone could tell me whether this is a cap or a pot, and possibly mesure theirs (if they have a P990) or direct me to a schematic that would be so helpfull.
Thanks alot.

Hi I assume the part you are refering to is RV904, this sets the EHT.

With this part removed the EHT goes low the reason the picture is wide it would also have been too tall.

You can not just put another pot in its place unless you have the facility to set the EHT or you know how the old was fitted and can measure the setting of it so that you can match the new one to those settings.

By the way this is a Sony D98 chassis also used in the CPD-420GS.

Rich