CurtPalme.com Home Theater Forum

LOTREE · Posted: Mon Jan 18, 2010 7:45 am Post subject: Center focus issue

I don't recall having this issue before or at least that I have noticed since I mounted the projector on the ceiling. I honestly haven't used it all that much regardless but I can't seem to get the center of my screen on all three tubes razer sharp like I before.

The top part of the image is projected on the wall since the current screen is only 60" wide

As you can see I have no issue of sharpness in the corner:

It's not a screen or lens/focus issue as the image is being projected on the tube face the same way, I removed the lens to check.

I've adjusted the focus pots, flare rings, corrected some astigmatism, fiddled with R6 and R7 controls on the Waveform Module with no change. I'm at a loss what to check next aside from swapped boards. I just installed a new Dallas chip which I think was new OLD stock as it can't hold convergence. I did a reset and went through everything I can think of twice.

Any ideas?

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Looks like contamination in the optical path. Fungus in the coolant chamber, most likely.

What kind of PJ is this?

CJ

LOTREE · Posted: Mon Jan 18, 2010 4:08 pm Post subject:

ECP 4500. I considered fungus but the gylcol and face look clear unless it's such a light haze it can't be seen. I know the red tube has some on the front glass but it's a defined blob in the center. I just find it odd all 3 tubes are projecting the same in the same location.

**Curt Palme** · Posted: Mon Jan 18, 2010 4:19 pm Post subject:

Fungus. You won't be able to see that through the lens.

LOTREE · Posted: Mon Jan 18, 2010 4:28 pm Post subject:

I had the lens off and examined the tube last nite and couldn't see anything. But it could still be, I'll have to check again. Looks like another big project. I kinda want to take this apart to clean it anyway... there must be something wrong with me. Thumbs Up

**Curt Palme** · Posted: Mon Jan 18, 2010 4:47 pm Post subject:

Post a pix of the test pattern on the raw tube face. Play with the exposure time so the crosshatch isn't too bright in the photo, and post it. That should show splotches of light fungus..

LOTREE · Posted: Mon Jan 18, 2010 4:52 pm Post subject:

Will do! I should be home in oh... 7 more hours. Thumbs Down

LOTREE · Posted: Tue Jan 19, 2010 3:08 am Post subject:

Well, the prognosis is in and with a little tweaking in Lightroom maxing out the saturation and vibrance on the middle photos to show the difference it looks we have a case of the Fungi. The red I already knew about and shot that one through the tube. I had to angle a LED flashlight and fluorescent trouble light to attempt to get any shadows on the face. Luckily good ol' dad had a 1 Quart bottle of Propylene Glycol around he bought from TheChemistryStore.com when we considered cleaning the tubes in the BarcoVision 600 I do believe.

LOTREE · Posted: Tue Jan 19, 2010 5:35 am Post subject:

So I got bored and decided the red tube would look good on the kitchen table. Removing tubes is rather easy for the first time! Now to drain the glycol and clean it. Best to remove the glass or CLR it? I'll be doing the same on the green and blue tubes also.

km987654 · Posted: Tue Jan 19, 2010 8:14 am Post subject:

At what level is the contrast set??

LOTREE · Posted: Tue Jan 19, 2010 6:08 pm Post subject:

In the top photos probably 4. The rest of the images were taken with the projector off.

**AnalogRocks** · Posted: Wed Jan 20, 2010 1:30 am Post subject:

How are you going to tint your glycol?

LOTREE · Posted: Wed Jan 20, 2010 4:16 am Post subject:

I'm going to reuse what I have and top up with propylene glycol, about 1-2ml each, due to the wastage when taken apart and filtered. That shouldn't effect the color too much. Each tube uses about 55ml total. I was originally going to use new and tint with green ink and magenta printer ink per the write up on the site. I have the red and green done, taking the blue out now. Cool

And a little rum and Coke to help along the way. Thumbs Up

LOTREE · Posted: Wed Jan 20, 2010 7:35 am Post subject:

All done!

Red:

Tough stuck on fungus

I thought I'd try Permatex Ultra Black Maximum Oil Resistance RTV Silicone. I didn't know the GE Silicon was heat resistant, which was also 1/3 the price, until after I bought what I did.

Green:

Odd enough the green tube glycol is actually blue

Green all empty...

Glass removed

Dirt blower for small pieces of urethane and dust hiding in the corners of the tube, I knew I bought this for a reason Wink

Sealed again and taped

Blue:

Removing the bolts. Turns out the factory distance from the tube face to the lens mounting plate is the width of the tips of the included adjusting wrench . I made sure to check that before touching any of the tubes. Cool

Falling dirt in the lower right corner before cracking it open:

For now they're sleeping on the floor in the corner drying. Tomorrow I should have it all back together. I'll give an update on the final picture if all this work was worth it.

LOTREE · Posted: Thu Jan 21, 2010 6:44 am Post subject:

All fixed. I should have done a better job cleaning out the tube face, flushing with water, before putting the glass back on as I had a few small black pieces of urethane now floating or small pieces of dust and lint. I'll see how it works and if need be do the green and blue tubes over again. Overall it was rather easy just time consuming. Waiting for the silicone to dry 24hrs doesn't help.

Tubes dry and ready to fill. I put the glass on a bit snug so I was left with an extra 3-5ml of glycol from each tube, Oops. Works okay, just hope nothing cracks.

Now I just need to fix the color shift: