I have an optoma ep749 projector that is shutting down after about 5 minutes of use. Lamp time is 165 hours. Fans seemingly run well. But no matter what it fails. What can I do to fix this?

SOURCE: Toshiba TDP S8 projector shuts down suddenly

The reason why the projector is shutting off is so the lamp doesn't explode. It's more of a safety feature on the projector, you can reset the lamp and it might work for another 500hours. If the picture is still pretty bright I can get you the reset procedure, but be warn that when the lamp does eventually blow it could shatter the glass inside, so be careful, it shouldn't hurt the unit.

SOURCE: My Optoma HD65 Projector stops starts working and

Possible cause is overheating.
Do you hear the fan working?
What happens when you use the lowest level light output?
Does it run longer?

Also possible cause is a faulty temp sensor.
AC wire connection may not be firmly pressed in socket.

SOURCE: panasonic projector keeps shutting off

Try this utube link. I did it and it solved the problem in about 30 seconds! Don't spend any money or send out your unit. This does it.

http://www.youtube.com/watch?v=6jGwB05_gdk

SOURCE: Optoma H56 - turns off just after start up.

It's not a short, the blub is near the end of it's life ~ the optoma is designed to detect when the blub is about to blow and shuts itself down. Turning the projector upside down or right side up usually only gives you a brief reprieve (some have reported a modest amount of extra time gained) on the blub ~ but in the end it's on it's way out and the projector will shut down again.

SOURCE: panasonic projector keeps shutting off

http://www.youtube.com/watch?v=6jGwB05_gdk

5 minute fix guaranteed

worked for me