[cmjohnson]

Very odd.


I have just finished retubing the Marquee 9500LC that I have set aside for myself,

and am doing the pre-installation setup, and notice something really, really weird:


The green corner focus on the lens won't focus properly!


Electronically, the focus is very fine.


The LC assembly is the usual type for a 9500LC. Nothing out of the ordinary.


The green C element is the same one that was in this assembly when the old

green tube was in it.


The lenses are the same HD10GT17s that were on the projector before.


Scheimpflug works normally but can't fix this problem.


The center of the image can be focused perfectly, but I can't focus the left and

right central zones mechanically.


Electronic focus is just fine.



The only thing I can think of is that maybe, just maybe, I may have swapped

the green C element for another green C element that I have, which came from

an AmPro 4300's tube assembly. But why would that matter? Aren't all HD10

series C elements the same? I don't KNOW of any difference.


I don't want to have to tear down the entire assembly to find out. Particularly

when you consider that I secured the C element in place with some silicone

as I'd never expect to remove a color filtered C element for any reason.


I will start simple, by swapping lenses. See what happens.


Any thoughts on this?


CJ

 

[cmjohnson]

What, no suggestions?



CJ

 

[KBK]

something is twisted... the focus is in front of the lens position on one side..and behind on the other side. Only the center is focused. The usual focus problems. Boy, are you ever gonna feel dumb when you figure this one out.

 

[KBK]

check for lens seating? it might be off. that would require an entire 'side' to be off.....

 

[stefuel]

OK, c-elements are the same. I assume it was inspected and clean before you installed it. The red and blue seem fine? or you haven't got that far yet? Are you attempting to run the absolute largest raster you can squeeze out of it? If so, that may be the problem. HD-10 lenses are optimized for a 7 inch diag 4:3 image. I know that sounds stupid but that's the way it is. Just of kicks, try to focus it with a smaller raster size.


Chip

 

[KBK]

I'm suspecting the silicone might be the issue. that does not sound pleasant..but....it might lead to a badly seating lens..and that would lead to....(IIRC the Marquee LC set-up correctly. it's been a few years)

 

[dochlywd]

KBK,


Who let you out?! What are you doing lurking around here?! Get back to turning that 1292 into a G90 triple stack!


That's it! No more of your "over our heads" posts that our primitive minds can't even begin to understand for at least a week, young man!!!!!!!!!!!


Mike

 

[KBK]

How's mike doing with the fix? Any idea?

 

[techman707]

I agree with KBK, maybe you didn't seat the C-element properly when you seated it in the silicone.


Obviously you need to swap the lens and rule that out. How far out is the focus?


Although I've never seen this problem myself, VDC claims that a c-element can become "etched" from running high contrast on a high hour unit and that it can affect the focus. Apparently you have to look carefully with the c-element off to see it good.

 

[KBK]

if the focus problem is exactly even, top to bottom, left to right, then it is likely to be a simple binding spring or hex bolt issue, as opposed to the silicone job...as it is very unlikely that you made a boo-boo with the silicone....and it is perfectly straight.

 

[Dave-Roth]

I had the exact same problem with an ECP I was setting up. IT was also the green tube. For the life of me I could not get all four corners to focus. I finally decided to remove the lenes to see if there was something wrong with the lens.. After removing it and inspecting it everything looked fine but while I had it off I decided to switch it with the blue lens. Like magic, the green now focused perfectly or as perfect as a SD187 can focus. Since blue on on an ECP is never in focus, it was hard to tell the difference with the switched lens on the blue tube.


I still don't know what the problem was but switching them worked.

 

[techman707]

Quote:

Originally Posted by KBK if the focus problem is exactly even, top to bottom, left to right, then it is likely to be a simple binding spring or hex bolt issue, as opposed to the silicone job...as it is very unlikely that you made a boo-boo with the silicone....and it is perfectly straight.

Where are there springs on a Marquee LC assembly?

 

[cmjohnson]

I'm running a reasonable raster. The problem is very pronounced in the green assembly,

but the red and blue are perfectly fine.



I swapped lenses and got the same results.



I then removed the entire assembly, took the C element retainer plate off,

and compared the green C element I installed with the one I had as a spare.


Guess what?


They're different.


And I had definitely inadvertently swapped them.


I just got done doing the fastest teardown and reassembly of a Marquee 9" LC chamber

assembly in history. One hour to disassemble the front end of the assembly, cut out the

coolant chamber, remove all residual silicone, put in a new one, and reassemble it.


The silicone will dry overnight and tomorrow I'll put the glycol back in and then it's back to test.



Beware. C elements made for AmPro's implementation of the LC assembly are apparently

DIFFERENT than the C elements made for Marquees and other units that have the C element

in a fixed location relative to the lens.


On AmPros, the C element is fixed relative to the CRT and LC assembly.



I will be confirming this tomorrow.


CJ

 

[Clarence]

Don't trash those ampro c elements. I have a 4200 that might need some. The phosphor is minty, but there's a little funky gunk somewhere in the lenses. I haven't inspected them enough or disassembled to determine where in the lense assy the specks are.

 

[Dave-Roth]

Quote:

Originally Posted by Clarence Don't trash those ampro c elements. I have a 4200 that might need some. The phosphor is minty, but there's a little funky gunk somewhere in the lenses. I haven't inspected them enough or disassembled to determine where in the lense assy the specks are.

Speaking of Ampro, Clarence, Did you ever get around to doing a proper comparo between the 4200 and the Marquee?

 

[Clarence]

I just got it delivered but now I'm on the road again for the next month or so. I'll try to get it cranked up and tuned in on the weekends.

 

[cmjohnson]

I will not toss any C elements. Never.


CJ

 

[dochlywd]

(Excuse me while I sneek in here)


KBK,


You should be getting it really soon. He knows our situation and that you want this off your plate, so he has no problem supplying it to you. The MP5 has him tied up at the moment but that's coming to an end as it goes to market.


(Sorry for the interuption. I'll butt back out now)


Mike

 

[cmjohnson]

The repair is complete. I was right. The new (old) green C element is the correct one and

edge focus is what it should be.


Beyond any doubt, the C elements made for AmPro are not the same C elements made for

Marquees and other PJs that hold the C element in rigid alignment with the lens barrel.


You may want to file that away for future reference.


And now, I have the IMMENSE pleasure of owning a 9500LC with a full set of brand new tubes!


Actually, the tubes are NOS, AmPro refugees, taken from AmPro PJs that were

never completed and sold in that condition at the AmPro bankruptcy auction.


They're P19LCP07s. I modded all three neck cards to run with them.


I noticed a while back that if you simply remove the no. 6 pin socket (and of course the

resistor linking it to ground) that the result is that the flying G2 lead will fit on the tube pin,

but not with much safety as the length of engagement is very short. My solution was to

drill out the pin socket hole in the neck card so that the flying G2 lead goes completely

through the board and seats fully on the neck pin.


This is quick and easy and makes for a connection that is every bit as secure as the G2

connection on a regular tube installed in a Marquee.


CJ

 

[KBK]

Quote:

Originally Posted by techman707 Where are there springs on a Marquee LC assembly?

I'm talking about the focus. you know. top bottom, let right. Very short screws on the LC assembly, compared to the air coupled versions. and, to add, the springs are weaker. It can sometimes (but only in people unfamiliar with the assembly) lead to top-bottom, left-right focal issues..and be a bit confusing, at first. But he ain't a newbie. so, it was unlikely..but I mentioned it anyway. Gotta cover the bases.