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Jamesp
Joined: 28 Mar 2011
Posts: 3
Location: Beaufort, SC
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| Posted: Thu Apr 21, 2011 7:14 pm Post subject: Marquee 9500 circuit protect |
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Hello, This is my 1st post here. I'm an electronics tech on flight simulators. We use the Marquee 9500 projectors. I am the primary tech for fixing VNB issues with the projectors. I have 2 neckboards with the same issue and I am hoping to find a solution. One is a 02-270339 and the other is a 03-270340. Both go in fault protect and will not turn on the high voltage to the tubes. I have changed both Q13, and Q17 twice. no joy... I was thinking this was a short across the transistors, but im starting to think its in the 5V rails. Does anyone have any tips that will help. Also, I am looking for a troubleshooting guide, if it exist... which goes beyond a basic overview of the marquee projectors. I have repaired over 50 in the last 6 months and needed something a little more in depth.
BTW does anyone have a good inexpensive source for MRF 549 transistors?
Thanks,
JP
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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: Thu Apr 21, 2011 7:26 pm Post subject: |
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Hi James, generally we/I don't post specific troubleshooting methods as that's how I make my living, and I'd be shooting myself in the foot if I gave that info away. Short of the s/manual, I don't think there's any in depth troubleshooting manuals, E'home never made any that I know of.
I do have some used neck boards at $20 each that you can steal the transistors off of, that's what I sell to most of the military customers that I have. I'll PM you with a couple of ideas as well.
Cheers!
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Thu Apr 21, 2011 7:28 pm Post subject: Re: Marquee 9500 circuit protect |
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| Jamesp wrote: | Hello, This is my 1st post here. I'm an electronics tech on flight simulators. We use the Marquee 9500 projectors. I am the primary tech for fixing VNB issues with the projectors. I have 2 neckboards with the same issue and I am hoping to find a solution. One is a 02-270339 and the other is a 03-270340. Both go in fault protect and will not turn on the high voltage to the tubes. I have changed both Q13, and Q17 twice. no joy... I was thinking this was a short across the transistors, but im starting to think its in the 5V rails. Does anyone have any tips that will help. Also, I am looking for a troubleshooting guide, if it exist... which goes beyond a basic overview of the marquee projectors. I have repaired over 50 in the last 6 months and needed something a little more in depth.
BTW does anyone have a good inexpensive source for MRF 549 transistors?
Thanks,
JP |
Hi JP, It might not be a problem on the VNB's but could be the VIM. You'd have to do some testing of voltage spots on the VIM
where the circuit protect is. An extension board will be needed for that.
For the MRF 549 you would need an older style VNB and scavenge them from there. Those parts are rare and expensive.
Curt might have some older VNB's hed sell you.
Check you Private message as well.
Athanasios
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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: Fri Apr 22, 2011 12:50 am Post subject: |
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Hi James, remember to make 4 more posts so you can respond to your private messages.
...and welcome to the forum.
_________________
Tech support for nothing
CRT.
HD done right!
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Tim in Phoenix
Joined: 21 Oct 2006
Posts: 4409
Location: Phoenix
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| Posted: Fri Apr 22, 2011 1:38 am Post subject: |
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Hello
It is often mentioned here that suspect Marquee neckboards can be ruled out (or in) by disconnecting the 14 pin umbilical cable; if the high voltage comes up then that neckboard is suspect.
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