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Zolzar
Joined: 26 Jun 2009
Posts: 252
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| Posted: Tue Mar 17, 2015 7:10 pm Post subject: NEC 10PG Conergence Issue? |
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I turned in the PG last night and the have a strange issue. I still need to test further since Inwas limited in time but the blue and red tube outputs are distorted. When I select the input the projector re-syncs and momentarily puts out a proper picture the goes haywire. I reseated the system board and wave boards no change. I did notice when I unplug the CA cable from the drive board and plug it back in everything is fine for a brief second and then flaky again. STK chips going bad? I'll post some pictures later after work.
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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: Tue Mar 17, 2015 7:39 pm Post subject: |
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Pull the point board out. They can do that, as can the system board or the convergence output board.
Have you recapped the boards yet?
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Zolzar
Joined: 26 Jun 2009
Posts: 252
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| Posted: Tue Mar 17, 2015 10:16 pm Post subject: |
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Hey Curt. I disabled the point board and low and behold the problem is gone. I know there are two schools of thought surrounding the point board....use and don't use but personally I like to tweak it to perfection using the pint board. I'll pull the point board and look at it. Otherwise I'll spend some time setting up without it.
I have recapped the projector. Did that about two years ago.
I still have my Marquee 8500 as a backup should the 10PG fail. What sucks is I only have 2000hrs on the 10PG chassis and about 1500 on the tubes. Hate to have to give up this beast with so little use.
John
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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: Tue Mar 17, 2015 10:42 pm Post subject: |
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Im guessing you didn't recap the point board? Regardless of how the set is mounted, check the caps for leakage, and you'll most likely find eaten traces. Depending on the damage, some can be repaired, others are writeoffs. that's why I stopped repairing all PG sets as of 2 years ago. Far too many problems and time to repair boards, only to have another one fail months later. If you've recapped already, then chances are you'll be OK, either with or without the point board.
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Zolzar
Joined: 26 Jun 2009
Posts: 252
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| Posted: Tue Mar 17, 2015 10:43 pm Post subject: |
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Update: pulled the point board and reseated all the chips. Confirmed Dead. Time to tweak the standard convergence settings.
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Wed Mar 18, 2015 12:13 am Post subject: |
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There may be two schools of thought surrounding the point board, but one is correct for all installations, the other is for those that dont care about perfect results.
The point board is there for perfection, and there to be used. If youre happy enough without it, thats great, but i wouldnt be.
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Barco Cine 9, ,Sony VPL570ES 4K SXRD, 135" OZ Theatre Majestic 16:9 screen, Denon X6700in preamp mode, 2x 7ch Tonewinner amps, 2x Tonewinner 15" subs, 2x 10" subs, 7.2.6...
RUNCO DTV991 LC ( NEC XG 852 LC ) 100" 4:3 screen, H/K AVR 7.1...
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Zolzar
Joined: 26 Jun 2009
Posts: 252
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| Posted: Wed Mar 18, 2015 10:19 am Post subject: |
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The point board was recapped but it may have been too late as there is some damage down by the six caps in the lower corner of the board. I'll yank the board this weekend and take a look at the prints and see if anything can be done to bypass the damage.
As far as perfection is concerned...I feel I have invested way too much time in the setup and calibration to simply go without the point board. I will either repair this one or seek a replacement.
John
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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: Wed Mar 18, 2015 1:47 pm Post subject: |
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There is another 10 or 100uf cap on the other side of the board, by itself. If that one leaks, it eats away a single trace that provides power to a chip very close to it. Check that. A couple of times I've been able to jump the trace and get it to work again.
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Zolzar
Joined: 26 Jun 2009
Posts: 252
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| Posted: Fri Mar 20, 2015 12:24 am Post subject: |
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I went over the board very carefully. I cleaned the board and re soldered the replacement caps. I went over this thing with a loupe. I found a few areas of concern but nothing concrete. The board still does not work. It's dead.
Anybody have any spare NEC PG Point Boards laying around?
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Fri Mar 20, 2015 12:38 am Post subject: |
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Yep.
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Barco Cine 9, ,Sony VPL570ES 4K SXRD, 135" OZ Theatre Majestic 16:9 screen, Denon X6700in preamp mode, 2x 7ch Tonewinner amps, 2x Tonewinner 15" subs, 2x 10" subs, 7.2.6...
RUNCO DTV991 LC ( NEC XG 852 LC ) 100" 4:3 screen, H/K AVR 7.1...
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Zolzar
Joined: 26 Jun 2009
Posts: 252
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| Posted: Fri Mar 20, 2015 10:10 pm Post subject: |
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Case,
I'll keep you mind mind if my local source doesn't work out. Thanks!
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Sat Mar 21, 2015 2:50 am Post subject: |
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No worries mate. I think i have two that work, and another two that dont. Got loads of PG parts here.
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Barco Cine 9, ,Sony VPL570ES 4K SXRD, 135" OZ Theatre Majestic 16:9 screen, Denon X6700in preamp mode, 2x 7ch Tonewinner amps, 2x Tonewinner 15" subs, 2x 10" subs, 7.2.6...
RUNCO DTV991 LC ( NEC XG 852 LC ) 100" 4:3 screen, H/K AVR 7.1...
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Zolzar
Joined: 26 Jun 2009
Posts: 252
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| Posted: Mon Mar 23, 2015 8:10 pm Post subject: |
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I got a new point board. There is something interesting in the new one. There is a cap soldered between pin 10 in IC825 and the DAREF test point. The board works fine but I am curious as to what purpose the added cap serves.
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mac
Joined: 07 Nov 2012
Posts: 143
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| Posted: Mon Mar 23, 2015 8:39 pm Post subject: |
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| Zolzar wrote: | | I got a new point board. There is something interesting in the new one. There is a cap soldered between pin 10 in IC825 and the DAREF test point. The board works fine but I am curious as to what purpose the added cap serves. |
That cap would only be required for a little more stabilization of those 2 power lines or there is a break in a trace somewhere in that circuit. There is a factory cap already across those 2 lines (C784). Pin 10 would be Vcc and DAREF is DAC Reference (4.5v).
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Zolzar
Joined: 26 Jun 2009
Posts: 252
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| Posted: Mon Mar 23, 2015 9:10 pm Post subject: |
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Cool. Thanks!
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