I have a mitsubishi wd 65738. My picture suddenly went dim. I can still see a picture but the room has to be very dark and its still hard to see. Do I just need to replace a bulb?

Did this problem happen all of a sudden or did it happen over time?/
Let me know.

TRY GOING IN MENU AND AJUSTING PIC QUALITY
INCREASE THE BRIGHTNESS , IF YOU CAN

did u touch the lens or bulbs when u cleaned it? It could be a color wheel problem but i think u should try to reset light tunnel. Did it give you any warning? or did it just all of sudden go dim. I gave u a link to a trusted YOUTUBE tech.. i use his work all the time.
See if any blink codes come up if u disconnect a bulb..good luck
chad man

did you do the self check for errors this set has? you can click the make a comment button and reply if you need help.

the green flashing light does not make sense if set is working.

As far as a dark picture if lamp not replaced or replaced with a generic it may be nearing the end of its life, many will dim just before failing.

Kindly adjust brightness/contrast/sharpness settings. If there is no improvement, this might require attention by a qualified service technician.

The tv projection lamp have problems,it shorting out some how.That why,u have a dim picture.Tries websites like Partstore.com,Ebay.com to buy a new projection lamp for the replacement.New tv,call mitsubishi for a warrenty repair.

Clean the lenses and try to adjust the colors in the menu.

Replaced the lamp.

If the tv looks now dark this is the first symptom of a lamp replacement (refer to the user's manual to do this job) and get a Mitsubishi original replacement.
the best picture setting (when the lamp is back of course) depends in the light of the room.
Now if after replacing de lamp and playing with the settings and the screen still pale, dimm, not enought color. a cleanning in the reflexion area is needed. (technican job)