I am looking into buying an InFocus LP690 Projector off of Ebay. It is stated as the light not working (assuming it just needs a new 200-300 dollar lamp). What are the possabilities of maybe using a 400w LL light kit and building a new box to house all the compnents in? Let me know what you think.

Recieved the projector last week. After some research and following this thread on DIYaudio, I tricked the projector into thinking the factory bulb is installed. I shorted the +5v and ground going onto the mainboard from the ingniter. I also disconnected the igniter from the power supply. I hooked up the projector to the vga out from my laptop, the 3lcd setup in this projector started up. I can see an image and everything seems to be working, except I have no lamp.

I am looking for some input on a good bulb. Something extremely cheap with no ballast would be ideal, however I realize this pj had a 200w UHP bulb. My initial thoughts are to build a light box on the outside of the pj and using a mirror at 45 degrees inside the original lamp housing reflect the light into the pj. I will post pictures if that will be helpfull.

Excellent buy you can use LED's if you don't need to much output I only need 30 to 40 Lumen with one 3W Led I get now 5lumen but is possible to get min 8 lumen from one 3W LED so with 5 white LED and 2 Red I will get about 45 to 50 lumen I also use commercial projectors see my PLOG

Well I found out why the projector was so cheap ($75) shipped. The green lcd seems to be bad. However, I took the lcd off of the prism and plugged it into the zif connector for the red lcd. The vertical lines disappeared. Plugged the red lcd into the green lcd port and it seemed to work as well. Is there any reason this would not work?

Another problem is one of the brown locking mechanisms for the zif connectors is missing. This could have been the initial reason the green lcd was not working. Where can I find just the brown locking mechanism?

And the final problem. There are glass plates after some other lens, and before the lcd with some sort of colored plastic sheet. On the blue lcd, there was a reddish one, but the plastic was all burned up. How could I go about replacing that?

I tested the projector last night with a 20v halogen lamp from a desk light. It seemed a bit blue in my opinion, but I was projecting onto a yellowish painted wall about 5 feet away with a 30 - 40 inch screen. When I held a sheet of paper up about 2-3 feet (minimum to focus) it looked great, just a bit dim. With a brighter lamp I am hoping it will be better. The lp690 was rated for 2000ansi lumens. How do I determine the lumen output of the 200w UHP lamp? What is a good target?

Electrodacus, interesting plog. What would it cost to implement a similar setup?


Also, if I do determine the green lcd really is toasted, would it be possible to replace? It is a 0.9" lcd. If not could I possible use the optics for a 7"-12" lcd screen?

After some more testing tonight, I determined the zif connector is the culprit of all the problems. I switched the green and red lcd's back to their respective locations and everything seems fine. The blue lcd is no longer connected because of the missing locking mecanism. I took the locking mechanism from the blue lcd and put it on the green lcd's connection. The green and red lcd's looked good.

What is my best option for finding a replacement locking mechanism? Also, I still need to replace the plastic film on the glass piece for the blue lcd. Althoug maybe with some more testing it will not be important.

The LEDs look like a good option. What would be a comparible setup without a ballast? Thanks for the suggestion on the leds.

Sorry to hear about you problem I got 2 projectors from ebay first a telex P600 for 95$ and second one a InFocus lp920 for 56$ .
The big problem of LCD projectors is the UV from the bulb is destroying the LCD in about 2000 to 4000h so most of the used comercial projector are not in good condition.
The first one Telex P600 was only 800lumen with 120W UHP and low hour so the LCDs are in perfect condition but the other one InFocus lp920 had a 230W UHP lamp and 2200lumen but the blue LCD have a yellow spot from UV and probably more hour.
The LED's don't have IR and UV so it will be the best option for a LCD projector.

shouldn't there be a glass IR shield for the lamps? The infocus I have has a glass IR shield.

Well I have some work to do for senior design on autocad so this will be a short post, more to follow later tonight.

I found a zif connector locking mecanism on an old hard drive that worked out nicely, it looks exactly the same as what was on the pj. So as far as I know all 3 lcds are working. I hooked it up to my laptop and it looked alright. I am using a small 20v halogen lamp to do tests. It did look a bit yellow at first, but then I went into photoshop and drew some test colors.

Blue looks black, and black looks blue, not good. I will try to take some screen shots, but I know my digital camera is not going to like the dark.

I will also take some pictures of the pj taken apart so that everyone can see the lenses, and 3 lcd setup. I will also show the lense that got burned up before the blue lcd (assuming this is why my blues look black etc...)

Till later...

the yellow tint could be partly attributed to the fact that you are using a halogen light which will have a yellow/orange push.

Okay, sorry about the lack of pictures. They are coming. Senior design has really been keeping me busy. Stayed at school over spring break to get most of it done.

Unfortunatly my halogen bulb stopped working, so no more test bulb. I am still considering a MH setup because of the large amount of knowlege on the forums. LEDs look interesting though. I found these rgb leds. I can't figure out how many lumens per watt they produce.

But my thinking was I could drive each color at the voltage required to get the best color balance. I figure I can fit 6 of them on the cpu heat sink I have laying around here. It is roughly 70mm X 50 mm. It will be a tight squeez into the pj, but I think I can manage. Let me know if this even sounds feasible.

Also what would be the best way to drive these leds. I have some knowlege of circuits and am always up for a challenge. So would it be possible to tie into the pj's psu at 120v and build a circuit to scale down to the required dc voltage?

Thanks in advance.

Hi have you thought of using a high intensity lamp like a xenon?

These can be obtained very cheaply and in 55w and 100w varieties for cars. I have the 100w without a ballast and it gives out some very intense light. I m planning to use it in an old projector. I got them from ebay for around $18 for a pair. They are 4500K 'super bright'.

I also found a set of 50 mm diameter hemispherical stainless steel bowls (set of 4 for $5) in Ikea. I ground a slot into the base and the xenon sits in there nicely. A great reflector/lamp combination.

Okay, I found this set of 'xenon hid' lights.

Are these what you are talking about?

My understanding are these are just halogen bulbs with a blue coating on the glass and a small percentage of xenon gas. This would be great if it works out, but what about heat. I would be terrified of putting a 100w halogen bulb into the small space in the projector. So if the amount of heat these bulbs put off is in the same range I am not sure if it will work.

Although, I could build a nice enclosure for it outside of the projector and reflect the light with a small mirror at 45 degrees in the light chamber itself. Then add some fans and make sure it stays cool.

Also I am assuming these run off of 12 volts DC. Just like in my previous post, would there be a way to build a circuit to convert 120v ac to 12v dc? And if there is a way would it be cheap, or am I better off buying a power supply?

Thanks

Yes thats the one, or similar to the ones I bought. They work well and in my small test, of connecting them to a car battery, the metal parts got hot but you would need a holder. The lamps run off a 12v DC supply so yes you would need either a converter or a power pack. I would think that a small plug pack would work. I would be very surprised if there is not a 12v source inside the Infocus. Have you tried probing with a meter? Try the connectors at the existing lamp and the fan supply.

As far as the 100w in a pj is concerned mot commercial projectors run at least this and they have a fan system built in. I don't think that this would be a problem. I have seen a number of projects using a replacement lamp within the enclosure.

http://www.instructables.com/id/Head-Light...ector-Mod-V1.2/

http://www.instructables.com/id/Halogen-Wo...-Projector-Mod/

Okay I think I am going to try a halogen headlamp for some testing, and if it works well try 1 or 2 xenon hids as the final. My only concern with the auto headlamp.

It runs on 12 volts, and I want around 100 watts out of the bulb. This means 100 watts / 12 volts = 8.33 amps?

This means I need to find a 12v source @ 8.33 amps correct. I doubt the projector has a 12v source with 8.33 amps, but I also could be completely wrong with these calculations.

Hi,
Your calculation are fine I will suggest to use 50W bulb . Your bigger problem is that the light in this comercial projector must be strait as a laser beam not more than 5 degree will be used so you need a reflector for the bulb or you need lenses or reflector for LEDs.
The RGB LEDs are 3W about 1W/color I don't now the lumen output for this LED but Is better to buy an white led and if necessary add a red or blue led.
I will use 7 led 5white one red and one blue see my PLOG
Maybe cheaper and easier is to use a 50 xenon but you need to find a good reflector that send a good spot not more than 5 degree or smaller than 10cm spot at 1m distance.

Hey...Im tring to build a DIY projector as well and Infocus-LP725 seems similar to your one. I was wondering if i should buy it (if i can get it for cheap) and put a new bulb. The thing is on their site it says they use a '150-watt Metal Halide' bulb so does that mean i can replace the bulb for a cheap price(since it would come with a ballast Im guessing) compared to the commercial bulb? On another site it said that they use "150W UHE" bulb?? so i a little confused...so anyways, i also want to upgrade the lcd but these use "3.3 cm 3LCD". Would it be possible to use a say 7" lcd latter on if i wanted to?
thanks

No that wouldnt work because the lenses on it are made to project up to 3 1/2" lcd panels, meaning no! that wont work but scouring the internet for truly dead 3lcd projectors might. Id imagine you'd find what you need for cheap.