CurtPalme.com Home Theater Forum

[redfox001]

When I measure the peaklumens from my Marquee 8500 ultra I get a value that is way to low however when I measure the ansi lumens they are pretty high.

I have two crt's in my ht at this moment, a nec 6pg at the ceiling and a marquee 8500 ultra on a table. I projected the same image that is a windowed white and measured the ftl from my screen. With the nec I measure 12 ftl but with the marquee I measured 6 ftl. The same measure on a full white screen gives 5,3 ftl for the marquee and 3,7 for the nec. The image is 1080p.

So somehow the marquee does not produce the peak lumens that it should.

Also strange is that green seems limited at intermediate contrast. Above 50 green does not get much brighter while red and blue go through the sky. The wear on all the tubes is very low.

I'm thinkin about interchanging the green tube because I have a marquee with spare parts but I can't understand the peak problem because also red an blue do not seem to peak much. They all stay about the same bright when I go to a windowed white screen.

I use the eye one pro that does a fine meaurement on the nec so that can not be the problem.

Any help is appreciated because I'm at a loss right now

[Nashou66]

Are you sure the G2 levels are correct? And also what is the hour count on the PJ.

Also read this for doing an eye adjustment for greyscale then do the eye one adjustments.

http://www.etechvideo.com/techtip1.htm

This is from Tims site.

Inability to see the second darkest square with G2 below 75 for any color indicates a worn or damaged tube.
The need to set Red Drive above 60, or Blue Drive above 75 also indicates weak tubes.

if any of this is true then your tubes are not having the proper emission and need to be replaced.

Athanasios

[redfox001]

[Nashou66]

Take a pic of the stair step patters of all tube colors with G2 .

he states that if you cant see the second dark square with G2 below 75 you have low tube emission.
but this is difficult to grasp , at G2 set to 75 you should be able to see the second dark square very distinctly.
now on the red and blue the talks about the Drive also, not the G2.

here is what my settings are on my bran new tubes with 65 hours.

Where I can barely see the second square.


Red
G2: 57
Drive: 14

Green
G2: 58
Drive: 95

Blue
G2:63
Drive: 48

The closer you have to set any of those th what Tim listed means your tubes are getting weak.

Athanasios

[redfox001]

I was reading a bit to fast I see.

My G2 values are all below 75 so that does not indicate worn tubes.

My drive values are

red d 23
green d 90
blue d 35

So that does not indicate a problem on red or blue but the problem is with green I'm afraid and he doesn't offer a way to test this.

But I've been doing some work today and I interchanged the neckboard on green, this did not solve the problem of green contrast not going high enough. So the neckboard is ok.

I've interchanged the little video rca jackets for red and green and also this did not sove the problem. So not in the video chain.

I still have to interchange the g2 wires and will do that later to see if the high voltage is the problem.

But these results seem to eliminate the electronics with the exception of the high voltage at this stage.

I also saw that the filament is allways glowing even if the machine is not on so very likely greens filament is toasted with the 50000 standby hours (2000 active) because I can see no wear. The question rises if it is posible to repair a tubes filament? And if this is costly.

I'll try changing the complete green tube tomorrow hopefuly the other one is better

[Nashou66]

Yes I was going to say your Green is close to the end of its life. You may be able to get a decent pic raising the G2 a bit more.
the Drive on the green does not affect the change as much as the drives of the blue and red so if you dont notice much change with green drive dont worry.

Athansios

[mp20748]

[redfox001]

I think I found something.

It seems the g2 wire is the problem. I set alle color drive and g2 settings to 60 to do a fair comparison. Then I connected the green g2 to the red and then the red had very low lumens at contrast 50 and 60 much lower than before.

Then I left green away and connected blue g2 to green and green had much more lumens now than before.

Now my question is, it seems to be the green g2 wire that is giving the wrong voltage but does this mean I have to change the high voltage unit? I got one extra!

[redfox001]

[redfox001]

Hello, I replaced the HVPS and after 10 seconds of nice functioning the horizontal sync suddenly shifted very much of. I think I heared a relais switch and then the white testimage shifted vertical leaving a black area in the middle.

Eventhoug I checked how the colors responded with contrast and it seemed much brighter. So that is the positive side, the HVPS fixes the problem with the lumens it seems.

Now what could have happened? I checked all the wires ten times, nothing wrong. I can even watch dvd but it is all shifted vertical.

I added a picture. Someone knows more?

[Nashou66]

Try using the vertical phase adjustment? I have not seen that bad of a fold over before. I have gotten it on just the edge of the bottom or side, but never that bad. Anyone else on this?

Athanasios

[Tim in Phoenix]

Hello

Looks to me like the vertical distortion is the control board or deflection processor. Try a Nashou-style cleaning and reseating of the control board and dpb socketed chips and interconnecting pins.

[Elaine Benes]

That was one of the things my current Marquee did while I was having issues with it. Yes, a cleaning certainly seemed to take care of it, for the time being...