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barclay66
Joined: 27 Jun 2011
Posts: 1304
Location: Germany
TV/Projector: Marquee 9500 Ultra
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| Posted: Tue Dec 13, 2011 10:06 pm Post subject: |
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Hi,
Yes, this is the Focus/G2 board. The connector next to the green one is the common G2 input. So this grey block has one input and three (R/G/B) outputs. Leave this connector alone. Only the three cables going to the tubes are relevant for the test. As You can see they are color coded and normally have to match the colors of the pots that You can see next to them.
Regarding the heater glow: Each tube has a heater filament which -as its appropiate voltage is applied- will show an orangeish glow. This is necessary so that the thus heated cathode can emit electrons which -after having been accelerated- hit the phosphor coating at the inside of the tube's faceplate and make it emit light. So, no heating, no picture...
Regards,
barclay66
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barclay66
Joined: 27 Jun 2011
Posts: 1304
Location: Germany
TV/Projector: Marquee 9500 Ultra
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| Posted: Tue Dec 13, 2011 10:16 pm Post subject: |
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Hi,
| TonyM wrote: | | Just a couple of other things that I noticed: on the amp board there are LEDs with text that says: "LED must be off at correct G2 setting in G2 adjust menu". When I have the PJ powered on all three of these LEDs are lit up. |
You can ignore those at this moment. Mine are also lit at normal operation and picture is perfect. They are only relevant when using the menu-guided G2 adjustment procedure and I know of several Pro's which don't even use this procedure for setting the G2 values.
| TonyM wrote: | | Also, we built a hush-box for it when we had it up and running the last time, and we took off the plastic cover of the PJ. Is that a bad idea for air circulation which might have damaged the blue tube somehow? I have two fans mounted in the hush-box itself for extra cooling, but still. |
I don't think that this will have contributed to the current situation. Overheating most likely will result in failure of Power Supply or Deflection related boards as those produce most of the heat.
Regards,
barclay66
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TonyM
Joined: 11 Dec 2011
Posts: 19
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| Posted: Tue Dec 13, 2011 10:21 pm Post subject: |
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Ok, interesting stuff! I just swapped the green and blue G2 cables and now all three tubes came on including the blue one! What to make of this?
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TonyM
Joined: 11 Dec 2011
Posts: 19
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| Posted: Tue Dec 13, 2011 10:22 pm Post subject: |
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Also I noticed the glow at the base of the tubes.
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barclay66
Joined: 27 Jun 2011
Posts: 1304
Location: Germany
TV/Projector: Marquee 9500 Ultra
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| Posted: Wed Dec 14, 2011 9:03 am Post subject: |
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| TonyM wrote: | | Ok, interesting stuff! I just swapped the green and blue G2 cables and now all three tubes came on including the blue one! What to make of this? |
Yeah, puzzling isn't it?
Especially as I now have to admit that one information I wrote above is complete nonsense!
The cables that You now have swapped aren't the G2 lines. They carry the focus voltage.
I realized that some time after my last post. I'm sorry for this and I attribute this fault to the late time I was writing it (around 11pm at my place).
Please see the picture below for reference.
But at least You managed to get some useful information out of this:
1. The blue tube isn't dead
2. The blue tube's neck board isn't dead
3. The blue tube's video amplifier board isn't dead
4. Touching the Focus/G2 board has changed the situation
So I'd suggest that You first mount everything back to original and give it a try.
If the blue tube acts up again You could try some tapping on the Focus/G2 board. Use something isolated like the plastic handle of a screwdriver and give it some gently knocking from different angles. Maybe the Focus/G2 board has some bad solder joint or other connection problem. This would explain why You had all three tubes working after touching it.
If You dare to go further You could unscrew the two bolts (marked green in the picture) that hold the Focus/G2 board in place and reseat it. Just pull it out and plug it back 2-3 times.
It is too possible that one or more of the potentiometers for G2 and Focus adjustment went bad (the one G2 for blue is marked in the picture). As the splitter/adjustment block is sealed this would result in the need for a new board.
Just for clarification: Swapping the focus cables wouldn't have much effect on the tubes regarding light output. A bad focus connection just would render the picture being out of focus.
Regards,
barclay66
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TonyM
Joined: 11 Dec 2011
Posts: 19
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| Posted: Wed Dec 14, 2011 12:14 pm Post subject: |
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Short update: Switching the blue and green focus voltage cables back after the test last night rendered the blue tube dead again.
I will try to reseat the G2 board later today and let you know how it goes.
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TonyM
Joined: 11 Dec 2011
Posts: 19
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| Posted: Wed Dec 14, 2011 4:10 pm Post subject: |
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Damn, I think I might have screwed up. Following some advise I received in a PM earlier I tried adjusting the g2 to see if the blue would come on. I turned the blue know clockwise and counter-clockwise a couple of times, but nothing happened. The blue still remained off. I then turned the red knob clockwise and the red became very bright. I immediately turned it back down, but when I look into the red tube now there are three thin diagonal lines going across from left to right, and one from right to left.
Did I screw up my red tube now? 
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Decibel
Joined: 31 May 2007
Posts: 904
Location: Roma - Italia
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| Posted: Wed Dec 14, 2011 4:16 pm Post subject: |
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I'm selling a focus/G2 board like your.
Do you want to try change it?
_________________
Domenico (Barco fan!)
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TonyM
Joined: 11 Dec 2011
Posts: 19
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| Posted: Wed Dec 14, 2011 4:59 pm Post subject: |
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See attached picture of the red tube. A little difficult to take a proper photo but the two lines going across the red area are more clearly visible with the eye than on the photo. I cant notice anything on the projected image at my screen though.
I hope I didn't destroy the tube this might be too difficult and I end up doing more harm than good.
[/img]
If it can fix the issues with the blue tube, and the red tube is still ok I would be interested in buying this card from you. But first I must be sure that this card is in fact the problem.
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Decibel
Joined: 31 May 2007
Posts: 904
Location: Roma - Italia
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| Posted: Wed Dec 14, 2011 5:33 pm Post subject: |
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you must lower the g2 level
_________________
Domenico (Barco fan!)
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TonyM
Joined: 11 Dec 2011
Posts: 19
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| Posted: Wed Dec 14, 2011 5:56 pm Post subject: |
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Ok, I lowered the G2 for red and the lines seem to have disappeared.
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TonyM
Joined: 11 Dec 2011
Posts: 19
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| Posted: Wed Dec 14, 2011 5:57 pm Post subject: |
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I will try reseating the G2 board like barclay66 suggested above.
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TonyM
Joined: 11 Dec 2011
Posts: 19
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| Posted: Wed Dec 14, 2011 11:00 pm Post subject: |
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I tried taking the G2 board out and putting it back a couple of times, but still no blue...
Any suggestions for further troubleshooting? Can we conclude that the G2 board is in fact the source of the problem?
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barclay66
Joined: 27 Jun 2011
Posts: 1304
Location: Germany
TV/Projector: Marquee 9500 Ultra
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| Posted: Wed Dec 14, 2011 11:48 pm Post subject: |
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Hi,
There is a remote possibility that the blue neck board might be the culprit (putting too much load on the G2/focus line). But this is very unlikely as the neck board only has few passive components on it which seldomly fail. Of course You can check if the blue neck board is correctly seated at the tube's socket and that there's not too much dust on it. Just compare with the other tubes. Failing Focus/G2 boards occur much more often. And mostly it's that sealed grey block with the pots.
So if You can get a working Focus/G2 board for cheap then grab it. You might need it sooner or later anyway. Just make sure You get a recent version (R762482-7). If its older it too will be OK if it has an additional small board soldered to it. The added board (incorporated into the -7 issue) is the so called G2 killer circuit which helps protecting Your tubes from spot burns and this is essential.
Good luck!
Regards,
barclay66
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