Author Topic: Troubleshooting a Samsung CRT SyncMaster 1100df  (Read 4288 times)

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Offline 13hm13Topic starter

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Troubleshooting a Samsung CRT SyncMaster 1100df
« on: August 14, 2013, 11:06:24 am »
The front panel pwr on/off push button has an "idiot" green LED light that indicates three conds:

ON (solid) -- on with signal (CRT should display input signal or monitor-generated menu)
ON (blinks) -- on with no input signal (CRT should display  monitor-generated menu or scrolling "NO INPUT SIGNAL" text message)
OFF (unlight) -- pwr off (main pwr push-button in out position), or no pwr (unplugged, damage, etc.)

I have solid on pwr button LED, but no CRT image -- not even Samsung's own internal-generated menu. Powering switch OFF and re-powering, I get the usual 2-3 sec delay and then the pwr LED turns ON.
All the ICs I can stick my probe on seem to be getting clean 5VDC. But the normal "bang" of the HV section does not happen. Dunno whether HV is bad or whether HV isn't getting signal to turn on.
What's weird is the solid pwr button LED, noted above. It should blink if there is no input connected. But it is solid regardless of the presence of input.

Any quick ideas?
Thx!!
 

Offline Psi

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Re: Troubleshooting a Samsung CRT SyncMaster 1100df
« Reply #1 on: August 14, 2013, 11:18:48 am »
Plug the monitor into a PC, so it should be showing an image, now put a torch right up against the screen at a 45deg angle.
Get in close with your eyes and see if you can see any image or patterns.

Sometimes the backlight dies but the LCD is still running fine.
« Last Edit: August 14, 2013, 11:20:31 am by Psi »
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Online PA0PBZ

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Re: Troubleshooting a Samsung CRT SyncMaster 1100df
« Reply #2 on: August 14, 2013, 11:23:19 am »
Sometimes the backlight dies but the LCD is still running fine.

Look at the 'CRT' in the subject...  ;)
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Offline Psi

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Re: Troubleshooting a Samsung CRT SyncMaster 1100df
« Reply #3 on: August 14, 2013, 11:41:47 am »
 :palm:
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Offline SeanB

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Re: Troubleshooting a Samsung CRT SyncMaster 1100df
« Reply #4 on: August 14, 2013, 05:38:46 pm »
Check power supply outputs, there should be a 100-150V rail to the LOPT area that provides power there. You can measure it at a test point by the power supply, which will have the voltage marked there. Common faults are the line output transistor pops or the LOPT has dry joints on the pins, or the tuning capacitors there have dry joints. Also common is the LOPT dying internally. Another fault is the CRT drivers on the input board going faulty, you will see the cooked capacitors and resistors there in that case.
 

Offline Tita

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Offline Stonent

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Re: Troubleshooting a Samsung CRT SyncMaster 1100df
« Reply #6 on: August 14, 2013, 11:30:20 pm »
Lick your fingers and touch random things, if you fly across the room, then the flyback circuit is working.
If you don't survive, then it was working very well.

 :-DD
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Offline G7PSK

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Re: Troubleshooting a Samsung CRT SyncMaster 1100df
« Reply #7 on: August 15, 2013, 03:18:07 pm »
Lick your fingers and touch random things, if you fly across the room, then the flyback circuit is working.
If you don't survive, then it was working very well.

 :-DD

That always works. >:D
 


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