CurtPalme.com Home Theater Forum

[the_maniac]

Hello,

I've got a problem with the focus on my 9500LC tube. I can't get as good focus as on the red and green. The lines of the convergence grid are about twice as thick as on red or green.

the G2 value's are: Green 64, Red 67, Blue 69 , should be ok or ?

already did Astig on tubes and got almost round donuts and centered flares.

also tried to swap focus connector between red and blue, no improvement.

now i'm going to swap the neckboard ... any other ideas what could cause this ?

regards

[cmjohnson]

Your central focus values are +/- 20 points from 50, so you're in the right range.

One thing to watch out for is that the human eye just isn't as good at seeing well focused blue images as it is with red or green,
so do your focus adjustments with the contrast turned way down while looking directly through the lens at the blue CRT face.

Be alert for signs of murkiness or coloration in the coolant. The CRT face should be white, not yellow, and without any yellowing toward
the corners. If there is any such corner yellowing, you need a coolant change and that may also be associated with a perceived reduction
in the sharpness of the image. It may look unfocused.

The neck card doesn't directly affect focus. It can introduce streaking or smearing in the image, but it can't actually mess with electronic focus.


Once you've swapped a neck card over as well as the focus plug, as a test, and the problem is the same, then the next step is to swap
the focus yokes between the blue and green tubes...but be careful when you do it. You wouldn't want to break a tube neck, I'm sure!

It is possible for the focus values to be in the right range but for the focus yoke to simply not be a very good one. There are six magnets in it, and they have to be pretty equal in strength. If some are weaker than others, it can make for poor focus no matter
what you do.



If the focus still won't come up on the blue tube after putting the green tube's focus coil on it, , you may be looking at a bad blue tube. This is rare.


CJ

[the_maniac]

once again tried to fix the problem blue focus is freaking bad, have swapped all connectors between red and blue but no change.

haven't swapped focus coils yet but maybe going to do it.

my problem was that i didn't know the problematique about fillament voltage for long time, so it was way too high when i first checked it.

g2 levels have rised to 65/70/72 in about 50-100 hours, so i guess my blue tube is bad.

[JustGreg]

Hi the_maniac,

It's broken and hopeless...send it to me and I'll give it a good burial...........KIDDING!

I got bored reading Chris' reply so don't know if he asked you if the problem started all at once out of the blue or after a repair; or if it never was right since you got the projector. Please elaborate.

Have you removed the lens on the blue tube to see if the grids are sharp at the tube face? If so, have you tried correcting the Scheimphlug for the blue to see if that doesn't fix it?

You said your "G2's have raised" in the last 100 hours....can we assume you're adjusting these levels using a colorimeter to maintain good color and that they aren't just creeping up by themselves?

I also had a blue tube with bad emissions in my Marquee 8500 that was caused by high P14 filament voltage before I got the projector but the image stayed sharp on the tube faces and screen even after adjusting G2's to compensate.

Maybe Athanasios will jump in and help out. Could it possibly be an aging/failing HVPS?

[the_maniac]

thanks for the quick reply

Picture is also bad on the tube face

Would it be possible to swap hv leads at the splitter ?
to be sure it' not a bad hvps.

I had set g2 by looking at the tube face but also by colr calibration, same results.

[the_maniac]

knowbody knows if it's possible to swap HV Leads at the Splitter ? or does this result in any damage to the tubes ?

[Nashou66]

You can change them no problems.

Athanasios

[the_maniac]

ok thanks, and the G2 Leads are those small connectors on the neckboard, should i swap green and blue ? (red is too short to reach the blue neckboard)

[dturco]