CurtPalme.com Home Theater Forum

gcom007

So, I suppose it doesn't matter which lens it is, but the particular HD8 lens I'm using on my green tube which I'm about to rip off or swap off or something is continually losing focus and causing just a heap of annoyance as fixing the focus means fixing 5 other things sometimes multiple times a day. Ridiculous. Is it common for these things to have issues dropping focus? It's not as if I'm not tightening it, though I've tried keeping it tight, loose and everything in between but it always flakes out. I guess before I start swapping, I just want to make sure there's nothing else I might be missing here. Any insight would be nice, but I've got a feeling the thing is just worn out or someone rocked it pretty good and never mentioned it to me. I should say, that this never was a problem until the last couple weeks as it's gotten colder so I'm wondering if that could have anything to do with it, but the red and blue have no issues. Thanks.

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

Swap the lens with one of the others to see if the problem follows the lens or stays with the tube first. It sounds like it's not the lens.

JustGreg · Joined: 07 Mar 2006 Posts: 3098 Location: Kenosha, WI

What brand is the pj?
I concur...it doesn't sound like a lens problem. If it doesn't rattle when you shake it when it's off, chances are the problem is electrical.
Heating and cooling are socketed chips enemy. Chip creep is common in electronics.
Generically speaking, pull all the chips and clean clean them and the sockets and reseat well. Check all connections and clean them and card edges. Check the green neck board for bad caps or swap in known good parts if you have any handy.

gcom007 · Posted: Mon Nov 10, 2008 11:39 pm Post subject:

The projector is a Barco 1208s/e. I have a whole spare set of parts to toy around with and I've been meaning to anyways to see if I notice any differences here and there. I'll also give everything a thorough cleaning.

The thing that's odd about it (maybe) is that it's not that I can't get great mechanical focus one I adjust the lens, it just doesn't stick, and again, it's only on the green.

And, I swapped out the lens with another I had lying around and again, same symptoms but they're actually a good deal worse with the new lens. It gets out of focus quicker and in a more intense manner. It just seems odd to me that it's not as if the image is any less in focus on the tube face when I compare the times that I have good and bad focus on screen. I don't have to make any digital adjustments sans to accommodate for convergence now being ever so slightly off. Just enough to be really annoying and really fun to fix on multiple inputs...

I noticed something though when doing some more adjustments last night. The scheimpflug adjustment on the green tube isn't quite responsive at certain points. Again, this very much seems like mechanical wear as there's tension and then no tension at certain points as well as no fine adjustment. So I'm wondering if perhaps the mounting assembly is a little flaky altogether. I'm thinking about swapping it out either way with some backups that I have just to fix that scheimpflug issue, but I'm wondering too if somehow it's playing into the bigger focus issue.

Cousin.It · Joined: 09 Feb 2007 Posts: 41 Location: Hurst, TX

Tom.W · Joined: 09 Mar 2006 Posts: 6635

I had the same thing happen on a BG 808s. Did the BG 1208s use the same cam system as the BG 1209s ?

gcom007 · Posted: Wed Nov 12, 2008 1:23 am Post subject:

Well, at this point, I'm thinking that this just boils down to the crazy temp changes going on in Michigan right now. The warm up cycle cleans it up pretty well and within a few minutes the issue seems to correct itself. Doesn't help that it's in a basement on the floor I suppose...but I'm glad it doesn't appear to be a bigger issue.

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

Warmup cycle? The white screen? Turn that off... it only uses up tubes. Your basement should be fairly stable in temperature unless it isn't very well insulated. Have you tried reseating the boards and looking for bad caps/bad solder joints?

gcom007 · Posted: Wed Nov 12, 2008 2:06 am Post subject:

Not yet but I'm still going to pretty quick and I want to swap in better mounting hardware too. And I'm not planning on keeping the warm up going. I just wanted to see if it'd help as it seemed to get better yesterday when I didn't do anything. I'll get it worked out...

And as far as temps, we've been fluctuating like crazy lately and not managing our thermostat well. Last week it was in the 80's and people were blasting the AC and then it was left like that into this week where it's in the 20-30's with snow. I just can't think that's helping anything because it really has been all over the map temp wise inside and out the last couple weeks.

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

Sounds like there may be some condensation happening too.

**AnalogRocks** · Posted: Wed Nov 12, 2008 5:33 am Post subject:

gcom007 · Posted: Wed Nov 12, 2008 7:49 am Post subject:

I'll tell you what, I'm down here now and I've been practicing the last few hours and I was hot at first and had to take off my sweater. I'm now freezing cold with a runny nose even. Funny enough, I walk over and check the projector and it's out of focus again...