yesur talking about CRT monitor right?
i think you might have to call the TV repair guy to have a look (probably need a replacement of certain part)
Even I have this problem. When I open the monitor sometimes the screen looks very dark and takes 3-4 minutes to come back to normal. Is this some bad hardware problem. Aren't there any solutions to it.
maybe buy those silica gel in a packets ..i think it is also called desiccant that you mostly find in bottle of medicine tablet..and also in some food package...to absorb moisture..
maybe stick those inside..the monitor..several of them...that might in a way help to control moisture...