Is it only on part of the screen or the whole lot?You could try applying pressure at the top of the LCD where the tabs attach, sometimes they age and detach and the picture gets soft/corrupted.
95% of the time this type of fault is caused by a faulty LDVS panel [T con ] This is the small PCB located at the top center of the screen covered with a screening can when removing it use extremecare with the ribbon cable / cables going to the screen