Sometimes screams a high pitched noise when turned on

It sounds like a worn or loose fan belt. It's slipping on the pulleys causing the screeching noise.

Are you getting a high pitch screaming or a grinding noise? The Fan on the heatsink sometimes getting clogged with dust and over time this can cause the computer to turn itself off. Dependant on a high pitch scream this could be a number of problems, memory modules loose or faulty?? Would need more info about the type of sound..

The power supply on this model will whine when it is shorted or overloaded - the set would have to be brought in to determine exact cause.

The color wheel is likely bad and needs to be replaced.
Check this link it is for a samsung TV but the same principals apply
http://www.jangro.com/electronics/samsung-dlp-replace-color-wheel/

the set probably has lots of bad solder connection on the flyback and in the horizontal deflection circuit.

buy a new tv

Can be either noisey yoke or noisey flyback transformer........T.

Use first quality OEM or equiv. transistor, RCA 237470 is
least expensive...............T.

I have a very high pitched sound and when I move the tv it will stop for a second or two and then start again. The sound sometimes stops all together. But very high pitch sound.

The high pitch squeal you hear is usually caused by a coil vibrating, normally in the horizontal circuit. I've also seen the ferrite bead on the horizontal output transistor do this, but, it is rare. I normally will repair this by finding the coil and "tightening" it. To tighten a coil, technicians use different chemicals, such as, a hot glue gun, rubber silicone or even finger nail polish. I will find the coil that screams by starting with the usual suspects and using a wooden dowel, barely touch the coil and if the pitch of the noise changes, then, thats the coil that needs repaired. If you do not know your way around the inside of a television, I never recommend you do so, since, this procedure must be done with the set turned on and you poke your hands around the inside of the set by the high voltage circuit. Hope this helps your decision.