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PiDD
Joined: 03 Dec 2006
Posts: 87
Location: Winnipeg, Manitoba
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| Posted: Sun Nov 16, 2008 3:45 pm Post subject: Marquee spot burn - help! |
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I posted earlier about my 8500 Ultra (MP mods) not powering up on the first try. It would power up on the HTPC input but it wouldnt always power up on the transcoder input. So I would feed it the HTPC and it worked ... no problem.
Until last night! I some friends over and we are rockin out rock band after the UFC fight when the green tube got really bright. Bright enough to see the 45 degree scan lines. I thought a power cycle would correct the problem. When I powered down the green blew. Its kinda hard to explain but the net result is a nice spot burn ... a little horz guy about 3" wide on the screen.
So needless to say I need another green tube .. but the big question is what caused it?
(if anyone has a green tube out there pls pm me with a price)
Thanks
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Sun Nov 16, 2008 4:39 pm Post subject: |
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Very likely Neck board failure. Before you get a new tube you need to check the neck-board and also the machine with an old burnt tube. I have never heard of this happening on a Marquee before.
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PiDD
Joined: 03 Dec 2006
Posts: 87
Location: Winnipeg, Manitoba
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| Posted: Sun Nov 16, 2008 4:53 pm Post subject: |
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| Quote: | | Very likely Neck board failure. |
I hope its not a neck board ... these are MP modded boards. Im not sure if he is still making them.
I do have a old green to test with ... hell I can test with this already burnt one cant I?
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Sun Nov 16, 2008 5:26 pm Post subject: |
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| PiDD wrote: | | Quote: | | Very likely Neck board failure. |
I hope its not a neck board ... these are MP modded boards. Im not sure if he is still making them. |
no but hopefully Curt will be soon. In the mean time, if you need to put in a stock card put it on Blue since it's focus is the softest no matter what.
| PiDD wrote: | | I do have a old green to test with ... hell I can test with this already burnt one cant I? |
yes of course, just started my coffee this morning 
When the Green went full blast it means a loss of G2 bias. G2 voltage is generated in the HVPS and sent to the VNB. It then loops back out of the VNB through the white wire and ataches to pin 2 on the tube clocking window. Check to make sure wire didn't fall off.
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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: Sun Nov 16, 2008 5:40 pm Post subject: |
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One thing with the Marquees... NEVER power down if a tube is too bright. THat's a rule for every set as well.
It's always better to leave the super bright tube on, it never damages the electron gun or phosphor, and either let the HV shutdown circuit work itself, or pull the CRT socket off the back of the tube, wait 30 seconds for all electron gun activity to cease, THEN power down.
Been there, done that too many times...
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AnalogRocks
Forum Moderator
Joined: 08 Mar 2006
Posts: 26706
Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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| Posted: Sun Nov 16, 2008 5:43 pm Post subject: |
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| Curt Palme wrote: | One thing with the Marquees... NEVER power down if a tube is too bright. THat's a rule for every set as well.
It's always better to leave the super bright tube on, it never damages the electron gun or phosphor, and either let the HV shutdown circuit work itself, or pull the CRT socket off the back of the tube, wait 30 seconds for all electron gun activity to cease, THEN power down.
Been there, done that too many times... |
I wonder if putting this info and info like this about other brands of projectors in a stickey in the main CRT forum would help people?
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PiDD
Joined: 03 Dec 2006
Posts: 87
Location: Winnipeg, Manitoba
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| Posted: Sun Nov 16, 2008 5:47 pm Post subject: |
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| Quote: | | One thing with the Marquees... NEVER power down if a tube is too bright. THat's a rule for every set as well. |
You know... now that I have sobered up ... I remember that!! As I was powering it off last night a little voice was saying stop. I didn't listen.
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PiDD
Joined: 03 Dec 2006
Posts: 87
Location: Winnipeg, Manitoba
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| Posted: Sun Nov 16, 2008 5:51 pm Post subject: |
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another thing I noticed... when I power up the green glows up first then a few seconds later the other 2 kick in.
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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: Sun Nov 16, 2008 6:16 pm Post subject: |
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No more stickies on the forums! Pretty soon they will take up the whole first page!
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PiDD
Joined: 03 Dec 2006
Posts: 87
Location: Winnipeg, Manitoba
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| Posted: Sun Nov 16, 2008 6:21 pm Post subject: |
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Here is a video of me powering on/off the pj. It starts to glow before the other .. then collapses ... fill the raster again ... turns on (to a windows screen - very bright) .. then I turn it off and see that cool looking explosion.
http://members.shaw.ca/pidd/8500green.mpg
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AnalogRocks
Forum Moderator
Joined: 08 Mar 2006
Posts: 26706
Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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| Posted: Sun Nov 16, 2008 6:21 pm Post subject: |
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| Curt Palme wrote: | | No more stickies on the forums! Pretty soon they will take up the whole first page! |
Yeah they are getting kinda deep aren't they?
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CRT.
HD done right!
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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: Sun Nov 16, 2008 6:23 pm Post subject: |
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Just sent Kal a message to maybe clean them up. I suggested ONE master sticky at the top of each forum that will then open all stickies. A few should be deleted as they are in the 'advanced' section of the main site as well.
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Sun Nov 16, 2008 7:08 pm Post subject: |
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| PiDD wrote: | Here is a video of me powering on/off the pj. It starts to glow before the other .. then collapses ... fill the raster again ... turns on (to a windows screen - very bright) .. then I turn it off and see that cool looking explosion.
http://members.shaw.ca/pidd/8500green.mpg |
That is weird yet cool at the same time!!! I have never seen that before but it looks like the Horizontal scan collapses
and then there is a G2 burst. I agree its most likely the VNB, the PJ should turn on with the VNB not connected, put the Blue VNB on the Green and see if it is still there?Leave the blue with no VNB connected and remove the HV lead for it as well. If it is still there then it could be more that just the VNB and maybe the green Horizontal
scan. But I think its just the VNB and the spot kill circuit has gone bad in it too.
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
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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: Sun Nov 16, 2008 7:16 pm Post subject: |
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ARe you sure the G2 lead hasn't fallen off the tube? It's happened before...
If not, then it could be a VIM, output board or CLM fault I'd say.
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stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
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| Posted: Sun Nov 16, 2008 7:25 pm Post subject: |
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| Curt Palme wrote: | One thing with the Marquees... NEVER power down if a tube is too bright. THat's a rule for every set as well.
It's always better to leave the super bright tube on, it never damages the electron gun or phosphor, and either let the HV shutdown circuit work itself, or pull the CRT socket off the back of the tube, wait 30 seconds for all electron gun activity to cease, THEN power down.
Been there, done that too many times... |
I torched a brand new 9" green that way
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Chip
A Barco is only a AmPro with training wheels
Card carrying member of the AVS chain gang.
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SisterOfMercy
Joined: 31 Oct 2007
Posts: 155
Location: Zwart Nazareth, The Netherlands
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| Posted: Sun Nov 16, 2008 7:31 pm Post subject: |
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| Curt Palme wrote: | One thing with the Marquees... NEVER power down if a tube is too bright. THat's a rule for every set as well.
It's always better to leave the super bright tube on, it never damages the electron gun or phosphor, and either let the HV shutdown circuit work itself, or pull the CRT socket off the back of the tube, wait 30 seconds for all electron gun activity to cease, THEN power down.
Been there, done that too many times... |
I've read this somewhere, but forgot what I had to do when such an event occurs. Would this also work in a Barco? This is also probably one of the only things requiring the PJ to stay on, right?
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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PiDD
Joined: 03 Dec 2006
Posts: 87
Location: Winnipeg, Manitoba
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| Posted: Sun Nov 16, 2008 7:43 pm Post subject: |
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| Quote: | | ARe you sure the G2 lead hasn't fallen off the tube? It's happened before |
Just double checked and its on. Just to be clear ... this is the white wire going to the bottom pin (ceiling mount) right?
I will swap VNB's next.
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PiDD
Joined: 03 Dec 2006
Posts: 87
Location: Winnipeg, Manitoba
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| Posted: Sun Nov 16, 2008 7:53 pm Post subject: |
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Well, I swapped out the VNB with the blue and get the exact same thing. Its not the VNB.
| Quote: | | VIM, output board or CLM fault I'd say. |
Is there an easy way to confirm?
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Sun Nov 16, 2008 8:02 pm Post subject: |
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Just swap with a known good boards, I wouldnt want to test your board in my PJ now !  If you have exteneder cards there are places on the Vim to to look for the proper Spotkill, Over current,and inhibit valeus that come from the CLM and the VNB's , but the spot kill circuitmay have failed and that needs to be fixed but it may have not since you shut it down first. I think eventually your HV should have shut down on its own but you jumped the gun and pulled the plug causing the spotburn like curt said earlier.
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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