I have read several times that some people believe that a PJ's on/off power cycle is the equivalent of 2-4 hours of lamp use...is this true?

I know mythbusters did this with 'all' light bulbs and came to the conclusion that the on/off was not that much and unless you are coming right back to the room or equipment to just shut it off.

Light bulbs and Projector Lamps are certainly two different animals.

Many tests on projectors have shown the more you spark the lamp the shorter their lives are. I won't turn my projector off if I think turning it back on is possible within a few to even several hours.

Thanks...

It's probably safe to assume that turning a projector lamp on and off is not good for it.

But what is definitely bad is turning on a lamp that has not cooled to room temperature. Never restrike a lamp that has not completely cooled. Many projectors won't let you strike a hot lamp, but must (if not all) will allow you to strike one that has not cooled all the way to room temperature.

Jim

I think the 2-4 hours of life per strike came from a post quite a while ago from Bob Williams, a former Infocus engineer. I would tend to believe him.

As BuffaloJim points out, most projectors will allow you to re-strike immediatly after the cooling cycle. The lamp has not cooled to room temp at this point. There is no real data that I know of that striking the lamp in this partially cooled state is worse than striking the lamp at room temp, but, the anicdotal evidence of re-striking after a short period and pre-mature lamp failure have been reported many times here. So, I'd say better safe than sorry.

Jonathan

I have the Epson TW700 which has a Blank button. I believe some have said that they blank the image rather than turning it off. Anybody know how effective this would be? I don't turn the PJ on every day, perhaps not even every other day. I seem to go in spurts. Any advice would be appreciated.

A quick Google search brought up a few reads below.

I personally never shut mine down unless the time span is going to be several hours and don’t fire it up unless I know it will be on for several hours.

I added an aux cooling fan to my setup and also a way to measure the temp of the air exiting the projector. If you want to read more about that there is a cooling link below in my signature. The aux fan adds a small amount of noise so I selective run it based on output temp, number of hours on and what the content being watched is.

http://www.digitalprojection.com/content/view/137/109/

http://www.projectorcentral.com/projector-lamps-faq.cfm

http://ask.metafilter.com/56090/LCD-Projector-Bulb-life-when-to-turn-it-off

http://hdtvmagazine.com/articles/2007/02/hdtv_tlc_extending_the_lamp_life_of_your_hdtv_microdisplay.p hp

http://projector.lifetips.com/cat/59693/projector-lamps/

http://www.projectorpeople.com/resources/projector-lamp_life.asp

I have the Epson TW700 which has a Blank button. I believe some have said that they blank the image rather than turning it off. Anybody know how effective this would be? I don't turn the PJ on every day, perhaps not even every other day. I seem to go in spurts. Any advice would be appreciated.

This would probably be OK for those short periods where you don't want an image on your screen, but you want to come back to watching something within an hour or so. But I wouldn't recommend blanking for extended periods of time.
Blanking gives you a (nearly) black screen without turning off the lamp... but that means your light engine and lamp are still running (and your lamp is still racking up hours).

The bottom line is probably to not cycle the projector on and off several times a day if possible and to allow it to cool as much as possible before restriking. If you do that, the lamp should hopefully 'live long and prosper.'

Jim