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csotranme
Joined: 06 Dec 2018 Posts: 6
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Link Posted: Mon Dec 10, 2018 6:17 pm Post subject: BG800 troubleshooting broken (main) powersupply |
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All,
As already mentioned in my other topic, the powersupply of my BG800 is broken..
At first sight it looked like something with the fuses.
I replaced them all today but still no luck.
Marked leds below are not showing any signs of life.
Boot behaviour is also a bit random. Sometimes the typical short repeating cycle with or without fans and a shutdown.
Sometimes after a few short cycles it stays on but blows a fuse (also a short blink of the scan fail led) marked here:
To be complete, standby powersupply does work of course, HTHD does too, during boot, the green led is flashing/on.
Any clues on where to look?
I'm almost at the point of trying to get new fuse holders and solder them on or sending it for repair..
Thanks!
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kal Forum Administrator
Joined: 06 Mar 2006 Posts: 17850 Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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csotranme
Joined: 06 Dec 2018 Posts: 6
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Link Posted: Mon Dec 10, 2018 9:41 pm Post subject: |
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Hi Kal,
Yes I did indeed, that's where I got the info about the LEDs etc.
To be sure I did pull out all the boards one by one but doesn't make any difference.
I also checked the soldering and it does look good to me.
Actually the fuse holder with the fuse that is breaking every time is a little bit loose to me but seems to be connected good enough though.
Also all the fuse holders are covered in white powder but according to Curt that doesn't hurt.
I can't think of anything else then the main powersupply but again I'm new to this stuff so I will try everything you guys advice me
P.s. I do have a spare BD800. Also broken powersupply (pulsing) but not sure anymore what it's overall condition is.
Have it stored somewhere else so I will take that powersupply to try as well next weekend.
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kal Forum Administrator
Joined: 06 Mar 2006 Posts: 17850 Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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Curt Palme CRT Tech
Joined: 08 Mar 2006 Posts: 24296 Location: Langley, BC
TV/Projector: All of them!
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Link Posted: Mon Dec 10, 2018 11:39 pm Post subject: |
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The big problem is that I don't even have an 800 test chassis any more. Sounds like you may have a short on a board, which is then taking out the power supply.
Thing is, the 800 is now 27-29 years old. Many parts and capacitors are going to start to fail. Change the two 100uF capacitors on the gate of the MOSFET transistors on the power supply. Those were known to fail, shorting out the MOSFETs.
Other than that, I'd really upgrade the projector to a newer one with better performance.
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km987654
Joined: 25 Jul 2007 Posts: 2852 Location: Australia
TV/Projector: Barco BG809s
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Link Posted: Thu Dec 13, 2018 9:28 am Post subject: |
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Check that you don't have any bent pins on any of your boards. I had a similar problem and found a bent pin on a convergence tray board.
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