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Get the shutdown error code- After the Tv tries to turn on and shuts down do not reset or unplug, go up to the front panel, press and hold MENU + DEVICE (INPUT) until you see a light on the front start to blink a two digit code like 3 blinks pause 4 blinks repeat, or 5 blinks pause 6 blinks repeat, or 6 blinks pause 6 blinks repeat, etc. What error code did you get?
Inspect the lamp- Has the lamp ever been replaced, when? Find the trap door where the lamp goes, unplug the Tv, take the lamp out and look down inside the glass part. Is it clear and in tact or is it dingy, cracked, bulging, shattered, etc?
Good job! 6-6 error is LAMP. Since it has never been changed, that is the very first thing you need to try (even though it looks ok visually). Lamps are designed to run for 4000-6000 hours then they need to be replaced. Here is the lamp you need: http://www.advancedlamps.com/Genuine-AL-915P049010-RPTV-Lamp-Housing-for-Mitsubishi-TVs?gclid=CIGohMXF9qcCFQRMgwodABTCZw
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