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Vermin
Joined: 11 Sep 2009
Posts: 32
Location: Germany
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| Posted: Fri Sep 11, 2009 11:09 am Post subject: Maquree LVPS to much red. |
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Hi there and Greetings from Germany.
I have a Problem with the LVPS from my Marquee 8000.
The red tube is too bright. This manifests itself mainly in the Peak Brightness area of the Tube. G2 Level is ok.
This fault arises only when the projector was separated from the Power. If i let him at the Power Supply for 1 day there is no more fault.
Since a few Weeks this behavior of the Projektor is gone. Now is always too much red on the tube.
I´ve changed the LVPS between my 8000 and 8500. The fault moves so that it is definitely the LVPS.
ähmm...G2 Level are ok (between 60 an d 65). Drive should be at R35 G90 B50 factory setup. I have try to Color Calibrated it with this to much red. Drive is R0 G100 B76 to achieve some measure to the 6500k at the higher IRE´s.
I´ve pull down Contrast to show what it looks like on the Tube surface.
Any Idea what happened with the LVPS?
http://www.2lss.de/2dcafe/gallery/displayimage.php?album=13&pos=4
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Fri Sep 11, 2009 12:17 pm Post subject: |
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That sounds more Like a HVPS not the LVPS. this is a way to test the voltages of the G2's on a marquee to help. this is from Tim Martin:
| Tim Martin wrote: | Posted: Sat Mar 22, 2008 1:00 pm Post subject:
Hello
Troubleshooting Marquee Video Problems Without A Scope
One does not always have the luxury of a dual trace scope on the road,
here are a few norms to test for if your Marquee has high voltage and
picture problems, like flashing, or no pix at all, or one color is weak:
Vim Mini Coax Levels, Unplugged From VNB:
With CONT of 40 and BRITE of 40, the tip of the mini coax feed
gives 110mv with internal stairstep, 255mv on white field.
Internal Pattern Sequence is 1) Hatch plus Dots,
2) Dots Only, 3) Stairstep, 4) Full White, 5) Source
G2 Values and Voltage, measured at tip of VNB R76:
G2 of 40 gives +375vdc
45 +415vdc
50 +462vdc
55 +510vdc
60 +555vdc
65 +600vdc
70 +646vdc
Fluke DVM dc limit is 655vdc and goes into alarm mode.
Brightness Control Line to VNBs, P13 Pin 8:
BRITE of 0 gives +2.02vdc
10 +1.59vdc
20 +1.19vdc
30 +0.81vdc
40 +0.37vdc
50 - 0.02vdc
60 -0.44vdc
We have observed Marquees with leaking glycol where this control
voltage was shorted to +5v on the MB and as a result the tubes shut
down for no apparent reason; you would think you had a bad VIM
or neckboard but it was not so. |
Maybe this will help diagnose the problem
Athanasios
_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Fri Sep 11, 2009 2:23 pm Post subject: |
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Can you post a picture of the actual screen with the stepped gray scale pattern?
I have seen this issue before with high hour sets, where the gray scale is OK until about 80 IRE, then the red takes over. I have not found the cure for this, but will work on it again when I see the next set that does it. It is not:
-VNB
-CLM
-VIM
-HVPS
-tubes.
-CCM
Last edited by Curt Palme on Fri Sep 11, 2009 4:35 pm; edited 1 time in total
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Fri Sep 11, 2009 4:34 pm Post subject: |
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Sorry, I tried that one too. Post edited. 
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Vermin
Joined: 11 Sep 2009
Posts: 32
Location: Germany
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| Posted: Fri Sep 11, 2009 9:37 pm Post subject: |
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The Picture i posted shows the gray scale at Kontrast 0-5. Thats the reason why there are so few steps.
Actual i have 2 Marquees. 8500 and 8000. The 8000 has an run time of 4100h and only on green a lite worn. The 8500 has an run time of 1300h and a worn with rating 7 on green and 8 an blue.
I decided to change the LVPS, HVPS and Neckboards from the 8500 to my 8000.
Both have since a few days Color Filtered Glycol.
Im waiting for an new HDM for the 8500. Shipping from USA.
Leak at the Anodecup. The high voltage jumped over into the Deflection Yoke. That was the death of the HDM.
Always the same problem with old tubes at the Anode Cups. The Anode was re-isolated at all Tubes. Safety first...
ähm...The 8500 has an CCM. The 8000 not. The LVPS makes the same problems in both CRT´s. Also the failure is direct in the LVPS.
When the new HDM arrive here i will test the LVPS with Tim Martin Checklist.
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Revox
Joined: 13 Feb 2008
Posts: 158
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| Posted: Fri Sep 11, 2009 10:35 pm Post subject: |
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I thought the set you've got was only 800ours in use, the rest was standby wasn't it? Vermins bought the second CRT from me.
It's totaly interesting, that the CRT community is so little.
I thought that the LVPS has nothing to do with G2? But i must have a look at the service manual.
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Sat Sep 12, 2009 2:11 am Post subject: |
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| Revox wrote: | I thought the set you've got was only 800ours in use, the rest was standby wasn't it? Vermins bought the second CRT from me.
It's totaly interesting, that the CRT community is so little.
I thought that the LVPS has nothing to do with G2? But i must have a look at the service manual. |
it doesn't except for it feeding the HVPS with the 390VDC line. thats the only thing I think could be involved. But like curt said he has ruled out all those boards if his problem is in fact the same.
Athanasios
_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Sat Sep 12, 2009 2:26 am Post subject: |
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I've only seen the red push on high hour (>20,000) sets so far. I'd like to see a screen shot of the stepped gray scale to see if it's the same as I've seen here. Of course I don't have a set here right now that does this problem..
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Vermin
Joined: 11 Sep 2009
Posts: 32
Location: Germany
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| Posted: Sat Sep 12, 2009 7:26 am Post subject: |
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OK.
I make a Screen shot when the M8500 is repaired. And then i will measure the Voltages.
I can describe what´s on the Screen.
The difference between IRE 0 and 20 on the grayscale pattern is visible on all Tubes at g2: 60-65 (Contrast and Brightness set for this on 50). The higher IRE´s are too much red. Drive red on 0 is even too much red on Screen. So Red is my limiting Color. I can compensate the white balance by increase blue and green but that is no good Setup for me.
DeltaE is not realy acceptable. This is only with this LVPS.
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