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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Wed Feb 15, 2012 10:52 am Post subject: Difficult Projector Problem |
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I have a barco 808s that I have put 9" tubes.
The problem is that after a few hours running the image flickers and dims. I have swapped out the SMPS, H-Shift, RGB Input and driver boards but the problem is still there. I noticed tonight that when the projector did that a TV in another room lost signal when I shut down the PJ (which I did right away) the signal returned so what ever the issue when it happens it affects TV reception. I swapped out each board one at a time not all at once. All three tubes flicker and dim. If I wait a few hours and restart all will be OK.
Any ideas.
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Wed Feb 15, 2012 11:39 am Post subject: |
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Over heating.
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Wed Feb 15, 2012 10:28 pm Post subject: |
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| CasetheCorvetteman wrote: | | Over heating. |
The chassis is unchanged where the frame is attached so the boards are cooled the way the factory intended. The RGB amps are in a modified section to accommodate the 9" tubes.
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tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
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| Posted: Thu Feb 16, 2012 1:33 am Post subject: |
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The TV in another room that cut out has an antenna connected or cable or what? The projector CRT amps can make nice RF transmitters which can cause interference. They can be tricky to modify because of the high bandwidth capabilities.
Scott
_________________
"Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
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barclay66
Joined: 27 Jun 2011
Posts: 1304
Location: Germany
TV/Projector: Marquee 9500 Ultra
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| Posted: Thu Feb 16, 2012 9:21 am Post subject: Re: Difficult Projector Problem |
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| km987654 wrote: | | I have a barco 808s that I have put 9" tubes. |
Hi,
Did You also change the deflection/focus/stigmator coils? If so, the new ones could have different impedance values and therefore create an overload situation in either H/V Deflection, Focus or Stigmation circuitry. This could lead in overheating and the described symptoms.
Also the 9'' tubes usually require higher HV than 8'' tubes. Did You modify anything in that area too?
And finally: What about the G2 voltages? Did You check that they match the new tube type? Flickering and dimming on all three tubes without changes in geometry could point to a problem on the SMPS/G2/Diagnostic board. You could take a look at its diagnostic LEDs. Do they change when the tubes start flickering?
Regards,
barclay66
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Thu Feb 16, 2012 8:52 pm Post subject: |
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| tse wrote: | The TV in another room that cut out has an antenna connected or cable or what? The projector CRT amps can make nice RF transmitters which can cause interference. They can be tricky to modify because of the high bandwidth capabilities.
Scott |
The TV has an antenna which is also in the house. I never notice this before now as usually the other TV is off. This time my wife was watching a favorite TV show when the signal disappeared. The yelling and screaming was a dead give away. I powered off the PJ and she got the signal back.
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Thu Feb 16, 2012 8:58 pm Post subject: Re: Difficult Projector Problem |
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| barclay66 wrote: | | km987654 wrote: | | I have a barco 808s that I have put 9" tubes. |
Hi,
Did You also change the deflection/focus/stigmator coils? If so, the new ones could have different impedance values and therefore create an overload situation in either H/V Deflection, Focus or Stigmation circuitry. This could lead in overheating and the described symptoms.
Also the 9'' tubes usually require higher HV than 8'' tubes. Did You modify anything in that area too?
And finally: What about the G2 voltages? Did You check that they match the new tube type? Flickering and dimming on all three tubes without changes in geometry could point to a problem on the SMPS/G2/Diagnostic board. You could take a look at its diagnostic LEDs. Do they change when the tubes start flickering?
Regards,
barclay66 |
All of the components are BG808s except the tubes. The HV components in the 808s are the same as those I used in my barco 1101 which also had 9" tubes ES though. As far as G2 voltages are concerned I have not modified those from what ever they were for the 808s. I have changed the SMPS before now with the same result. I usually switch off the PJ so I have not seen what those LEDs are doing which as you point out I should do.
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Thu Feb 16, 2012 9:00 pm Post subject: |
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| CasetheCorvetteman wrote: | | Over heating. |
Just thinking about this the RGB amps do get hot but I don't have anything to compare it to so I don't know if hot is too hot. I might add some cooling or improve the airflow by improving the current fan setup.
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Fri Feb 17, 2012 6:27 am Post subject: |
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I reckon add some more cooling and just do some testing, i dont know what its been like down your way, but its been bloody hot up here mate so i wouldnt discount the fact.
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Posted: Fri Feb 17, 2012 11:22 am Post subject: |
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| km987654 wrote: | | CasetheCorvetteman wrote: | | Over heating. |
Just thinking about this the RGB amps do get hot but I don't have anything to compare it to so I don't know if hot is too hot. I might add some cooling or improve the airflow by improving the current fan setup. |
My 808s neck boards are around 50 C (25 C room temp) after two hour run with 1080i96Hz, projector in ceiling.
Some other boards can be seen here.
https://www.curtpalme.com/forum_archived/viewtopic.php@t=13103.html
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barclay66
Joined: 27 Jun 2011
Posts: 1304
Location: Germany
TV/Projector: Marquee 9500 Ultra
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| Posted: Fri Feb 17, 2012 12:09 pm Post subject: |
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Hi,
Interesting pictures!
I wouldn't have expected that the HV Splitter would produce that much heat...
Regards,
barclay66
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HaydnG90
Joined: 22 May 2006
Posts: 1356
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| Posted: Fri Feb 17, 2012 4:02 pm Post subject: |
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Seems quite localized too. I would think that odd
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Posted: Mon Feb 20, 2012 9:07 am Post subject: |
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| barclay66 wrote: | I wouldn't have expected that the HV Splitter would produce that much heat...
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| HaydnG90 wrote: | | Seems quite localized too. I would think that odd |
Good catch. 
That "hot" HV socket seem to be connected to blue tube that was partly shorted that time, it arched inside tube few times during movie. I guess that might had something to do with that extra heat or my splitter is bad, have to check this again when I get theater ready some day...
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Motobias
Joined: 08 Jul 2008
Posts: 163
Location: Osnabrueck, Germany
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| Posted: Mon Feb 20, 2012 11:09 pm Post subject: |
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makes me wanna have a thermal camera 
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Tue Feb 21, 2012 7:02 am Post subject: |
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Id love to see how hot the base of a PG gets, i know you can hardly touch it...
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geisemann
Joined: 30 Nov 2009
Posts: 33
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| Posted: Fri Feb 24, 2012 4:29 pm Post subject: Hi |
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IF you have HV shutdown then you have a BAD quad or Tripper.
You could be driving the H width to high too and need a board mod. There is a extra Horz board on the 9 inch units.
Greg
www.eisemann-theater.com
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