I have a 5yr old Mitsubishi DLP WD-73827 tv with 2yr old DLP lamp. After TV is on for 10-15min the colors, mostly lighter colors, white, gray, etc, change, seem to glow somewhat. The clarity changes. Picture is still there overall but colors change and seem to glow in patches. (reminds me of a piece of metal with oil residue on it put in water, have "rainbow" type sheen on water surface). The LED light is green for the TV and no other colors or blinking lights. Is this a V chip or motherboard issue? How much to replace? Can I fix myself? I did manage to replace the lamp myself.