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Zolzar
Joined: 26 Jun 2009 Posts: 252
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Link Posted: Thu Feb 21, 2013 3:41 am Post subject: |
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I turned off the AKB in the menu and it did not eliminate the issue with the blue drive. Forgive my ignorance but is there a physical cutoff switch anywhere? Since it is only a problem with the blue drive what board should I examine? Video PWB? There is the distinct possibility this loss of control is due to an error while changing out the caps.
Thanks,
John
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gjaky
Joined: 05 Jun 2010 Posts: 2790 Location: Budapest, Hungary
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Link Posted: Thu Feb 21, 2013 2:48 pm Post subject: |
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Indeed, Video out PWB measures the tube current and can cut off the drive. TP3402 is the test point for blue tube current (TP3202 for green, TP3002 for red) You'd need an oscilloscope to examine these signals with eg. a full white test pattern. Of course these values shouldn't be the same, but will give an idea if the blue tube is really driven that hard, or the projector just thinks it is driven hard... As you probably noticed there are quite a few adjustments on that board and any of them could be connected to your problem, as the relation between the controls is very sophisticated.
_________________ projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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Zolzar
Joined: 26 Jun 2009 Posts: 252
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Link Posted: Thu Feb 21, 2013 10:01 pm Post subject: |
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I do have a scope so I can take a look at each. Thanks for the heads up on the test points. I also have the service manual so there should be something in there about the process......a process I'm sure is not easy to fully understand and can possibly lead to more problems. The first thing I will do is check my work on the board concentrating on the blue section. I could have accidentally hit one of the little pots on there too. I'll see what kind of time I have available over the weekend to dig into this. Thanks again!
John
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CasetheCorvetteman
Joined: 09 Nov 2008 Posts: 6319 Location: Australia
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Link Posted: Fri Feb 22, 2013 5:27 am Post subject: |
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I wonder if someone molested the G2 settings on that?
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Zolzar
Joined: 26 Jun 2009 Posts: 252
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Link Posted: Fri Feb 22, 2013 12:38 pm Post subject: |
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Given I am only the second owner and the original owner had it calibrated professionally I would doubt the G2 theory....however....G2 levels could still be an issue since when the picture muted the raster does not completely turn off. What do you think?
John
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gjaky
Joined: 05 Jun 2010 Posts: 2790 Location: Budapest, Hungary
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Link Posted: Fri Feb 22, 2013 12:44 pm Post subject: |
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That could be a clue, normally when the picture is muted, you should only see the raster when looking in to the lenses directly, what are your brightness and contrast settings?
_________________ projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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Zolzar
Joined: 26 Jun 2009 Posts: 252
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Link Posted: Fri Feb 22, 2013 6:38 pm Post subject: |
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I should have been clearer on my description. It is only when I look into the tube that I see the raster.
Contrast 75
Brightness 48
My biggest problem while setting up the grayscale was the blue tube drive. I order to compensate I had to drop the green drive to 50. I did not want to do this but this is the only way I could get all three tubes within 1% of each other on 30 and 80 IRE.
John
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gjaky
Joined: 05 Jun 2010 Posts: 2790 Location: Budapest, Hungary
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Link Posted: Fri Feb 22, 2013 7:09 pm Post subject: |
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I think the kelvin settings should be more in the 50ish range rather than in 70-80. Take a look at the HV power supply board if there is a switch on it (hormal/high bright) don't hesitate to switch it to high bright mode, 10PGs are not the brightest pjs amongst 9-ers, maybe you just pushed it too hard.
_________________ projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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Tinman
Joined: 09 Mar 2006 Posts: 1326 Location: Carson City Nevada
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Link Posted: Fri Feb 22, 2013 7:30 pm Post subject: |
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Green is usually at 50 - 50 and then set red and blue for grayscale. On the PG10 make sure the switch on the HV board is set for bright. I'm not going into the actual pot adjustments on the video out board since this is too complicated for most people to do, but that could also be the problem. Make sure you see where the tubes are in TEST mode on the video board. If everything isn't close in test, the board probably needs re-alignment. The 3 pots on the G2 module should all be set the same, or VERY close visually. Pushing the tubes too hard with the HV switch in low mode can cause pulsating.
Marc
_________________ This space for rent.
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CasetheCorvetteman
Joined: 09 Nov 2008 Posts: 6319 Location: Australia
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Link Posted: Fri Feb 22, 2013 9:21 pm Post subject: |
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I am not sure where my KELVIN settings are on th 9PG, all are under 50, on my XG the red is in the 10s, the other two are in the 20s... 100" 4:3 for the 9PG, 125" 5:4 for the XG, more than bright enough!!
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Zolzar
Joined: 26 Jun 2009 Posts: 252
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Link Posted: Sat Feb 23, 2013 3:46 pm Post subject: |
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I tried the bright switch and found it to be set on high already. I will pull the video board later today and check my cap work. If that isn't the problem I would like to take the next step in checking the pot adjustments. I'm not afraid to make any adjustments using a DMM and scope. The only way to learn it is to do it.
John
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Tinman
Joined: 09 Mar 2006 Posts: 1326 Location: Carson City Nevada
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Link Posted: Sat Feb 23, 2013 5:49 pm Post subject: |
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Zolzar wrote: | I tried the bright switch and found it to be set on high already. I will pull the video board later today and check my cap work. If that isn't the problem I would like to take the next step in checking the pot adjustments. I'm not afraid to make any adjustments using a DMM and scope. The only way to learn it is to do it.
John |
The only way to properly adjust that board is with the service manual that has the procedure in it.
But if it started doing this after you re-capped the board, I'd triple check everything there first anyway.
Marc
_________________ This space for rent.
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Zolzar
Joined: 26 Jun 2009 Posts: 252
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Link Posted: Sat Feb 23, 2013 8:09 pm Post subject: |
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I do have the service manual with the procedure. I read through it and my biggest problem is that I don't have an extender board. I'm getting a little ahead if myself as I still need to look at my work very closely.
John
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gjaky
Joined: 05 Jun 2010 Posts: 2790 Location: Budapest, Hungary
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Link Posted: Sat Feb 23, 2013 8:29 pm Post subject: |
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Zolzar wrote: | I do have the service manual with the procedure. I read through it and my biggest problem is that I don't have an extender board. I'm getting a little ahead if myself as I still need to look at my work very closely.
John |
Solder flying wires to the test points that's all, just make sure you insulate the unused wires
_________________ projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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CasetheCorvetteman
Joined: 09 Nov 2008 Posts: 6319 Location: Australia
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Link Posted: Sun Feb 24, 2013 2:16 am Post subject: |
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I dont see why youd have to have the settings up so high, should be way lower than that, which is why id check the G2 pots first cause i reckon if you need the KELVIN up in the 80s the G2 is probably too low.
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Zolzar
Joined: 26 Jun 2009 Posts: 252
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Link Posted: Sun Feb 24, 2013 3:37 am Post subject: |
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All of my W drive setting are right around 50 for each tube. Are you saying my contrast setting shouldn't be so high? I also did look at the G2 pots and they are all in the same position.
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gjaky
Joined: 05 Jun 2010 Posts: 2790 Location: Budapest, Hungary
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Link Posted: Sun Feb 24, 2013 12:10 pm Post subject: |
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CasetheCorvetteman wrote: | I dont see why youd have to have the settings up so high, should be way lower than that, which is why id check the G2 pots first cause i reckon if you need the KELVIN up in the 80s the G2 is probably too low. |
You should remember to my AKB sensing problem on my PG xtra before it started to dicking my blue W and B was less than 50, now I have to pull the B up to 75 to get the same result, and I didn't touch any pots, AKB can govern the given levels heavily. The best way is to measure the Cathode levels as per the service manual.
_________________ projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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Zolzar
Joined: 26 Jun 2009 Posts: 252
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Link Posted: Wed Nov 02, 2016 2:14 am Post subject: |
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I just wanted to follow up on the problem I was having with the Blue drive. It is repaired and has been for a while now. I found the problem in the re-cap job. I failed to install a capacitor on the blue drive op amp follower. Without this cap clamping down on the follower it caused an oscillation in the tube drive above a certain level thus limiting the adjustment range. All fixed!
Curt! Old thread here but the case I received the PJ in from NEC did say prototype on it. I do still want to take some pics and post them and see if there is anything special about this projector.
Maybe the serial number can provide some clues. #7300111 Anybody have any thoughts on this number?
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