Projector issue advice

[fsaviator]

As you all may have read I had a projector start to go out.  I was able to buy a used one on eBay for half the price it would have cost to buy a DMD chip to fix my original projector.

The replacement arrived and it works.  Swapping it out was very easy with the mounts I am using.  Very little adustment needed as it appears the viewable area on the two projectors was slightly different, even after ensuring all settings were the same.

Regardless it is installed.  The issue is it is MUCH dimmer/less bright than my other two projectors.  My originals all have about 600 hours on them but this one has 1500 on (no way of knowing if it was reset).  I have to assume the bulb has more hours and that is why it is dimmer.  Does that sound right?

What should I do?

A) replace the bulb with a new spare one I have?  I think I'll end up with the same problem in reverse?

B) swap out the bulbs between the two projectors so that they all have the same # hours again?

C) pull the DMD chip out of the working projector and put it in the old one?

I'm thinking option B but I have no way of knowing how the hours on the other components in the projector affect brightness.

The projectors are BenQ MP-772ST

Thanks!

Before and after:

[navymustang]

Isn't there a brightness adjustment you can make on the other two projectors and just dim them down?  That is the low cost solution.

But replacing all three bulbs would be what we do at the shop, and I know that is expensive.

[fsaviator]

There is, but it doesn't quite make up the difference.
I hadn't thought about changing out all three bulbs...
I think I'll swap the bulbs between the projectors and see if it helps.  If it does, I'll buy another two bulbs to have three on hand for the next change.

[fsaviator]

Well,
Option B was a failure.

I put the old (600Hr) bulb in the replacement projector so that all three projectors had about the same hours.  It helped a little but not much.  That tells me that something other than the bulb in the projector is responsible.  No point in buying new bulbs for all three as it doesn't look like it will help.  The replacement projector will still be duller/less bright.

My next attempt will be to return both projectors to starting configuration then take out the DMD chip from the replacement projector and replace the failing one in my original projector.  That should solve the pixel issues and as long as the DMD chip isn't the source of dullness, we should be good to go.

Here's pics to show the left (good) and center (good) and the center (good) and right (dark/dull/less bright albeit with a good bulb that matches the other two).

[blueskydriver]

Hey Warren,

Just curious, you said both projectors, the original rightside one that went dark first, and then the used one you put in it's place also was darker? I am sure you have checked this, but have you tried switching the cable inputs into either projector with the source going to the center projector?

It seems rather odd that this is happening to both projectors and even after you swapped the bulbs around. Years ago I had something like this occur and turned out it was my cable pins not making good contact, so I hooked up a new cable and it was fixed.

Are you using DVI cables or HDMI? Also, after you use another cable, how about switching the cable at the video card ports? Plug it into one of the other ones and see what happens. Next, try this old trick; disconnect all input cables going to all three projectors and then turn them. Assuming your projectors have a default screen, usually blue with a logo name, you should be seeing just that.

Now, what do all 3 projector screens look like based on brighter or darker? Are they all the same? If yes, your problem is not the projectors. If no, reset all 3 projectors to default new out of the box settings, and if you still see a darker screen on the rightside it's your bulb or color wheel, and less likely your chip.

One other issue might cause this and your projector is not broke, it is just set in economy mode. Your bulbs are rated for 3000-4000 hours life, but if you set economy mode it will reduce the power and brightness by 20%

Here is the link for your manual; checkout page 54:

http://www.projectorcentral.com/pdf/projector_manual_5057.pdf

Post back what you find out,

John

Edit: Please turn on the test pattern for all 3 projectors and see if the brightness levels are the same, but it is best to reset all projectors to new out of the box default settings before turning this on. See page 50 of the manual; link is above.

[fsaviator]

Hey Warren,

Just curious, you said both projectors, the original rightside one that went dark first, and then the used one you put in it's place also was darker? I am sure you have checked this, but have you tried switching the cable inputs into either projector with the source going to the center projector?

The original projector DMD chip is burning out.  The image is still the normal brightness, it just has one spots all over it from the chip.

The (used) replacement projector works fine, the image is very dim though.  I've reset it and programmed it with the same settings as my other two.

I took the bulb from the original projector and put it into the used projector but while a bit brighter, still substantially dimmer than the other two original projectors.

Are you using DVI cables or HDMI? Also, after you use another cable, how about switching the cable at the video card ports? Plug it into one of the other ones and see what happens. Next, try this old trick; disconnect all input cables going to all three projectors and then turn them. Assuming your projectors have a default screen, usually blue with a logo name, you should be seeing just that.

VGA.  These are connected to an analog TH2Go.  Not worried about the image quality at this point, not the issue and swapping to DVI wouldn't fix this problem.

Now, what do all 3 projector screens look like based on brighter or darker? Are they all the same? If yes, your problem is not the projectors. If no, reset all 3 projectors to default new out of the box settings, and if you still see a darker screen on the rightside it's your bulb or color wheel, and less likely your chip.

I run them in default already, and all three are  reset.  No change with the used projector.  Brightness is equal across all three with the original projectors.

I'm going to go ahead and just pull the DMD out of the used projector and put it into my original projector on Sunday.  I'll take the opportunity to also dig into my other two projectors and replace the thermal pads on the DMDs with Arctic Silver Thermal Grease just to make sure they don't fry as well. 

That should fix the problem by replacing the actual faulty chip and removing all the light projecting elements of the used projector (bulb/lens etc) from the equation.

Thanks John. 

[blueskydriver]

Hi Warren,

Okay, I will wait until you change the chip out, as this is very interesting indeed...

John

[fsaviator]

And I declare this operation...  a SUCCESS!!!!

I swapped out the DMD chip in my projector with the one from the replacement projector and all is good!!!!  White spot problem fixed, and using my three original projectors and bulbs.

Now I'm going to go back and replace the thermal pads in my other two projectors with Arctic Silver 5 thermal grease to ensure they don't burn out.