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Thread: What is the DMD board? (kinda long) |
    
New member Username: Jer_d
Post Number: 1
Registered: Sep-06
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| Posted on Sunday, September 10, 2006 - 01:17 am: |
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Have a hln437W -- great TV -- but a lightning storm 2 weeks ago seems to have fried it.
Bought a Service manual and a new lamp -- the lamp didn't work. Tried a Ballast. Nada
I see that I am delivering 381.5 volts into the ballast -- but no 5 volt signal seems to be coming into the ballast.
From the service manual this seems to indicate I need to look at the DMD board -- which is fine, I can -- but if it is not sending the 5 volts to the ballast board, what do I do? I don't see a DMD board for sale at samsung parts -- I see the light engine, lamps, ballasts, and the digital and audio boards -- but no DMD board.
Am I missing something here?
thx |
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Silver Member Username: Fyi
Dallas,
Texas
Post Number: 840
Registered: May-05
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| Posted on Thursday, September 14, 2006 - 01:41 am: |
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A ballast will deliver about 5kv (five thousand volts) to strike the UHP lamp into a plasma state. After that the ballast supplies a pulsing 65 volts to keep it lit. The source is from the power supply, not the DMD. If you think the set experienced a surge on the 110v line, I would be looking at the power supply for some failure.
Some parts are only available from an authorized Samsung repair center. They may or may not be willing to order for you. |
New member Username: Jer_d
Post Number: 2
Registered: Sep-06
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| Posted on Sunday, September 17, 2006 - 09:46 pm: |
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thx for the info on how the ballast operates. Still, though, I am measuring in 380 v in from the power supply which is what the manual says I should -- so I am leaning agaist the power supply as the culprit -- the DMD board sends in a 5 v control signal and I assume that is what tells the ballast board to blast up to 5 k and to pulse at 65
I could be measuring this wrong as I can't see where to put the blade electrode lead.
I also assume the DMD board would be like the power supply -- I'd have to call a repair center.
At this point this is just a fun project -- as I just got my HLS42662 replacement -- they really did move up!
Lesson learned -- during lightning storms unplug both power AND cable (I had my TV and Stereo on a surge protector -- but the cable wire in was unprotected -- that's the only thing I can figure)
thx again |
Silver Member Username: Fyi
Dallas,
Texas
Post Number: 846
Registered: May-05
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| Posted on Monday, September 18, 2006 - 07:20 pm: |
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Denny Young just found out that a bad "digital board" not the DMD board was keeping the ballast from activating. He was also able to convince Samsung to buy the parts if he covered the labor even though his "N" model was way out of warranty. Hope this helps your situation! |
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