Ship it back, our radiology department bought 6 LG Flatron monitors, all 6 have image defects in the LCD screen (blotches usually in the corner of the screens, or the top of them looks like the LCD pannel is melting).
The part that is playing up , is where you plug in the VGA cable, where the monitor CPU
and controls are. It has power transistors that convert the 5v from the inverter to 3.5v for it self
and 700mv for driving the signals to the panel. These are the larger -E looking blocks.
The diodes reading should be between 450 and 600 ish. Failing power convertions results in odd
behaviour in the card. typically getting worst as card heats up.
Manufacturer Part Number: EBU59489401
Board Numbers: 791501300700R
can be got on ebay
If cooling solves the problem, then dissassembling from inner and outer case and apply a house fan
would most likey extend the life before error of the unit. Rember your blue peter training, cardboard, keep fingers to side,
boards apart, using insulated material(also for resting parts on), parts reach 80 degree, 240v, so reassemble safely out of back casing, apply fan,
see if last longer before error.
Also a fix for other problems such as when resizing and power save cause unit to switch on/off in a loop
A replacement card is required when the units starts to loop on / off
after a period of time.