kortek K1-2-V0 13" monitor horz hold problem

[kardenm]

I have a kortek 13" K1-2-V0 monitor which has a couple symptoms.  Brought into shop because picture was to bright and could not be darkened further.  The game to which it was attached is supposed to have a blue background.  With the brightness controll turned all the way down the displayed game is a little to bright.  If the flyback is turned down to dim the game then the background goes to black.

I have replaced several bad caps and fixed some bad solder joints but don't see any change in this problem.  Also, the brightness controll (there is no contrast adj on this one) does not seem to actually do any brightness adjustment.  Rather, it just changes the color from blue-ish to red-ish.  There are nine color controlls on this board; RBG drive, gain and cutoff which makes balancing difficult.  I have been messing with all of these but don't seem to be able to correct the brightness problem this way.

Also have now noticed a new problem, maybe related to temperatures in the shop which drops very low overnight.  In the morning, after warming up the area, the picture comes up with the horz sync out of wack.  If I leave the monitor on, the picture eventually straightens up and looks normal from then on.

Any suggestion on where to go next with this thing, anyone??

Correction:  Shop temp overnight is not a factor.  If I shut monitor for half hour or so then turn back on, the same thing happens, ie. pic comes up out of sync then goes to normal after being on for a while (about half hour).