I found 2 different people on e-bay selling used "As-is" infocus projectors.

One guy had one that said it has a working lamp and posted a picture of it with the projector throwing a nice display.

The second one was half as much and just said no bulb no further testing was done.

I thought i could try the bulb from projector A in projector B to see if thats all it needs. Then i would order a new bulb and put it in the better of the 2.

I just got in the first one with no bulb and when i shorted the 2 pins on the lamp plug it fires up and everything seems to be working. I hear the color wheel spinning up and all the lights on the top seem to be doing the right thing.

Could there be anything wrong with the supply or anything that could cause it to throw to much voltage or anything into the only working bulb i have and blow it out? DO the supplys either work or not?

If i use a meter what would the output from the other 2 pins be that power the lamp? 12V? or more then that?

These are InFocus LP425Z projectors.

You're lucky you weren't zapped. Those projectors put out a very high voltage to "fire" the lamp and then settle in to a running voltage. Both are considerably higher than 12v. How much, I don't know and different units have different specs.

While it's possible the lamp ballast could have problems, it is usually a case of not being able to drive the lamp and it shuts down. Of course, a weak lamp could give the same symptoms. I have not seen a case where the ballast was putting out too much voltage and blowing the lamp. When a lamp blows, it's because it's old and weak.

You are Sheridan1952 the lamp must be weak or old thats why this sort of thing happen. You should be lucky that the bulb did not burst else your investment would be gone. I always prefer to buy new devices rather than used one, you never know if they might have problems, and you can also check these websites for new bulbs cheaper than the company rates.

http://www.projectorlampsworld.com

or

http://www.discount-merchant.com/

I got them both in and they both work but the one with the bulb has just over 500 hours on it. The bulb life is rated for only 1000 hours. Its either weak or alot lower in brightness then my others but it has a really nice image.

DLP projectors shoot a nice image but those color bars i cant stand. The image seems weird with DLP. I think i much more prefer an LCD type over DLP.

Ide rather give up a little bit of quality then to have those color bars.

I wish i didnt notice them so much.

Im having a weird problem with one of the projectors. It wont fire up a cold bulb but it will work fine if the bulb is warm. There is a thermal switch above the bulb that detects heat. It does somthign to the supply when it sences the bulb is warm and then fires the bulb up and works normaly.

The thermal switch is there to shut down the projector if the lamp gets too hot, which can happen if the airflow is blocked. I would have said, if a fan failed, but the projector is SUPPOSED to shut down if there is a fan failure.

What color bars are you talking about? A DLP is supposed to give an image every bit as good as an LCD. Unless you're referring to R.B.E. or Rainbow Effect. That is a byproduct of some DLP projectors, but most people don't seem to be affected by it.

Yeah the rainbow effect is what im talking about.

Well im not really forsure what the thermal sensor does but like i said when its cold it wont fire up the lamp but if the lamp is warm already from the other machine it works fine. So the supply is working but somthing else is not sensing properly or somthing.

I tried swaping the thermal sensors but that didnt do anything.

I told you what the thermal sensor was for. It is to shut down the projector if it gets too hot. It is either on or off, nothing in between. It will not sense whether a lamp is cold or warm.

Try this...if this cold fire problem is present on one projector, regardless of which lamp you try, but those lamps fire when cold in the other projector, then you have a weak lamp ballast in the first projector.

What is the ballast? in the power supply what is it?

Ive take the supply apart and looked in it but nothing looks burnt or damaged.

Is it just weak?

In most projectors, there are two power supplies.

There is the low voltage main power supply that powers the projector and then there is the high voltage lamp ballast power supply. Follow the lead from the lamp to find the ballast, but you will not see anything that will jump out and say I'm broken.

If you have performed the test I suggested and determined that the lamp ballast in that projector IS weak, there is nothing you can do. The ballast itself would have to be replaced and I did not see that assembly listed with my parts supplier.

And if you're thinking that you can get the service manual and troubleshoot it, you should know that Infocus does not have schematics in their manuals.

I just got in the first one with no bulb and when i shorted the 2 pins on the lamp plug it fires up and everything seems to be working.
I would really not recommend trying that again. I believe the initial "spark" voltage is somewhere in the thousands range... and i believe the current is also high enough to cause serious injury.
Though if you're measuring the stable voltage after the initial spark it should be under 100, which should be low enough to measure with a multimeter. However, as for the exact voltage, you'll have to do your calculations yourself, measure the stable voltage and the current and calculated wattage and see if its within range for the lamps rating (keeping in mind eco modes...etc). Though i only recommend this if you're somewhat experienced with electronics.

Edit: if its a problem with the initial firing... then you're out of luck unless you have some nice testing equipment, and so the only way to judge if its good is by sheridan's method.

Keep in mind that InFocus will not sell you ANYTHING other than the bulb. They will tell you to send the unit in, or quote you some outrageous price to fix it, so that you'll buy a new one.

Want to kill an hour one day? Try ordering a color wheel for an InFocus X1 projector. Try calling tech support, you'll get India. Call their sales line, oh, you'll stay in the US of A, but then ask to be connected to internal tech support. It was the most frustrating series of calls I ever made. The final straw was when the tech support guy told me that they wouldn't sell parts, they didn't have a repair facility to service the unit, but oh, did I want the part number of the color wheel?

So I lost it, and asked him what the **** good the part number is if no one sold the part?

Bottom line is folks, the lower end digital sets are designed to be completely disposable. That's why there are so many on eBay, most people won't even spend the money to buy a bulb to get their set going.