I've had the amazing luck to get a free infocus pl770 projector...

May 26, 2005 1:43 PM

I've had the amazing luck to get a free infocus pl770 projector. Can someone teach me how to treat this new toy right?

It was used in a school, but it would keep shutting off for no reason. I asked the parts guy and he liked me. So, wow! I have a projector! Anyways I fixed the concern: Too much dust in the front intake filter. (How sad, it may have sat in that warehouse for years for something so simple)

I have a white sheet set up against a wall to get the image and I am using it in a controlled light room. The image is clean and very bright. My speakers are set up behind the bed sheet. This makes for a cool setup, but the light definately bleeds through and softens the image.

My questions are this:

1. The bulb has 268 hours accrued but probably shut off and turned on a whole bunch of times before they put it out of commission. What is the lifespan of these bulbs?

2. What are some ways I can keep it bright and good looking for the years to come?

3. I don't have money. What are some extremely cheap ways to make the screen better?

4. Is this projector a good model?

posted by Dean Keaton to technology (9 comments total)

By the way, it is being used in a computer setup. Thank you for your advice. (Mefi at 80 inches)
posted by Dean Keaton at 1:49 PM on May 26, 2005

There is a forum here that has some pretty good information on cheap DIY projection screens.
posted by ktrey at 2:07 PM on May 26, 2005

and replacement bulbs are here(vv.expensive) --great find, Dean. If you ever want to sell it, email me.

You should hang the sheet flat against the wall...put the speakers in front. Art supply stores may have rolls of flat white paper that would work well too.
posted by amberglow at 2:24 PM on May 26, 2005

maybe keep it covered when you're not using it (unplugged too)--you should try to preserve the bulb life as long as you can.
posted by amberglow at 2:26 PM on May 26, 2005

With most projectors, a good piece of advice is to leave it powered for a few minutes after turning it off. This allows the fan to continue to run and cool the bulb/insides. Once the fan turns off, you should be safe to unplug it.
posted by thebabelfish at 3:35 PM on May 26, 2005

ScreenGoo turned one wall of my flat into a huge projection screen.
posted by blag at 5:41 PM on May 26, 2005

With most projectors, a good piece of advice

No. A flat out rule.

How to destroy a $400 (that being the typical cost) project lamp.

1) Allow the lamp to warm up.

2) Shake the projector.

To get lots of light in a very little space, they run a large amount of power through a small space. This gets very hot, worse, the filaments become more fragile.

The vast majority of early lamp failures is "salesman switches off and packs up the projector without letting it cool, and the filament breaks when he drops it into the case."

So, when the lamp is warm, the filament is much easier to damage. So, it is very important to TURN THE PROJECTOR OFF CORRECTLY. This usually means "Hit an off button, wait some period of time, then unplug." This does not mean "Turn off, unplug, pack away." The manual will tell you more, if you have one. Google otherwise, and see if it is posted.

If there's a soft switch and a hard rocker switch, turn off the soft switch first, then wait for the fans to stop. Then, you can turn off the hard switch, unplug, and pack away.

Finally, when you change the lamp, wear gloves. Projector lamps aren't as bad as some, as a class, but a general rule you break at your peril is *never* touch the bulb of a lamp with bare fingers. The oils collect on the bulb, and create a hot spot. There are theatrical lamps, rated for 200 hours, that will fail in minutes if they have a fingerprint -- and it will be very obvious that this is what happneed, since the bulb will have slumped from the heat where the fingerprint is.

There's some, but not convincing, evidence that this is true to some extent for almost all lamps, including 150W household lamps -- but the lifetime reduction is on the order of 5%. The one Joe Person is likely to encounter is lamps for non sealed headlights.

Short version: Wear clean gloves when changing the lamp.
posted by eriko at 5:38 AM on May 27, 2005 [1 favorite]

I realize that I've spoken cant.

lamp: what most people call a light bulb. It's the replaceable part that actually generates light in a lighting instrument.

bulb: the (usually) glass envelope around the things that actually make light. The bulb and the base are the things you can acutally touch in a working lamp, and you should only touch the latter with bare hands. (Easier to just wear gloves.)

switch, soft: A switch that isn't -- it sends a signal to something, which then control a real switch. Most notebooks have soft switches, which send a signal to the power unit to safely turn off the device. (This is how Macs ask if you really meant to hit the power button.)

switch, hard: a mechanical switch that physically opens a circuit. A normal wall switch is hard.
posted by eriko at 5:43 AM on May 27, 2005

eriko, that brings back memories of when I ran a spotlight in high school drama -- those rules were seared into my brain by our adviser. Ignore that advice at your peril.
posted by smackfu at 8:08 AM on May 27, 2005