Shutting down in the middle of presentations

sounds like it is overheating -- are the fans installed pointing the correct direction, all spinning up well?

http://www.manualslib.com/products/Sharp-Xv-Z3000-Vision-Wxga-Dlp-Projector-25348.html

SORRY - it needs a new lamp. It is a protection for the projector so the bulb doesn't explode.

I purchase hitachi projectors with 3 year bulb warrenties now for our school as cheaper in long term
good luck

hi,
To cool down the projector after use just press the Standby button and leave it in standby mode. The projector itself will cool down and will shut down itself. Only after this remove the power.
ok

clean all serface. clean power fan .

u have not mentioned how long u have been using this projector. either the lamp life is low or the circuitry protecting the lamp temperature is defective or even the air intake of the fan is inadequate, a filter is fitted for air flow if this is clogged or blocked, lamp temp will rise and unit shuts down. if lamp indicator is yellow or red it is time to change the lamp. if it is red - lamp is totally out, if u turn on the unit four times without replacing lamp, the unit simply wont turn on. one other possibility is power cable and power connections. check power cable too. 

the Fan has the problem , I had the same of yours. I noticed some particle was inserted in the center of the fan and removed it , worked perfectly. If old one produce little particles.
Good luck.

are there any leds on? if not, the power supply is shot. if there are leds on, the color and number of flashes will tell you the problem.

are any of the leds on the top of the projector lit? if so, which ones? red or green?

if none of the keypad keys work, it might be in lockout. if they do, the projector may need to cool down before it shuts down so the bulb won't retain the heat and cause damage. could also be button failure (or if the buttons are rubber, the contact underneath may be worn or dirty thereby causing no contact).