One half of the lcd tv loads fine, picture is perfect. The other half of the tv screen appears to struggle to warm up and appears much darker. In fact the image lingers when one program ends and another starts, almost like the previous image is burned onto the screen. After about 10-20 minutes the tv is working perfectly with crisp picture. Any idea what the problem is?

How old is your LCD TV?
From your description of the problem. It appears to be a moisture related. As the TV is ok after a while.

Power off your TV before carrying out next steps.

I would check the wiring connections first and see all connections are good. Also vacuum clean of dust using a brush is recommended.

Secondly would use a hair dryer to blow hot air into to TV unit via the exhaust vent. Just ensure that power is not switched on.
on your TV when you use the hair dryer.

i would also suspect a possible bad joint of a component on the mother board. A visual inspection is required to see the motherboard.

Also a component failure is a suspect due to aging..

You need to evaluate if it worth repairing the TV. Repair cost can be prohibitively high.

hope that helps. good luck.