Author Topic: Monitor Power Repair - Advise needed  (Read 827 times)

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Offline ohms lawTopic starter

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Monitor Power Repair - Advise needed
« on: June 23, 2021, 10:48:05 pm »
Good day all,

I need the power of the collective internet to help me identify the best approach to fixing my Monitor.

Problem this morning turned on the monitor it came on was dark and then screen was black - sound works fine as well as the PC know's it's there. I have 2 monitors connected to my PC.
My Philips BDM 4065UC was flickered a few times before turning on.

1.) Does anyone have a schematic for a 715G6985-P01-000-002R
2.) anyone know what the common causes of this type of failure



thanks in advance
 

Offline bob91343

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Re: Monitor Power Repair - Advise needed
« Reply #1 on: June 23, 2021, 10:53:27 pm »
Always test the power supply first.
 
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Offline Manul

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Re: Monitor Power Repair - Advise needed
« Reply #2 on: June 23, 2021, 11:17:13 pm »
Also test if there is really no picture or just the backlight is not working, aka flashlight test.
 
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Offline ohms lawTopic starter

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Re: Monitor Power Repair - Advise needed
« Reply #3 on: June 23, 2021, 11:19:46 pm »
The Logo comes on so there is picture - the logo is very dark however

it's as if the backlight driver has failed now not sure where that would be and how to test that properly
 

Offline Manul

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Re: Monitor Power Repair - Advise needed
« Reply #4 on: June 23, 2021, 11:30:51 pm »
On the top left corner of your first picture where "RoHS" logo is.
 

Offline shakalnokturn

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Re: Monitor Power Repair - Advise needed
« Reply #5 on: June 24, 2021, 07:48:56 am »
Check for voltage on the LED supply as mentioned by Manul.
Often a single defective LED is the cause.
A megohmmeter or any supply with enough voltage and current limiting can be used for a quick LED string check. You must get the polarity right first time though.
 

Offline Manul

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Re: Monitor Power Repair - Advise needed
« Reply #6 on: June 24, 2021, 12:37:35 pm »
As shakalnokturn said, it is probably LED failure. You can measure ouput voltage (if I read correctly from picture it is marked +VLED and -VLED). Measure with backlight connector connected and then disconnected. If the voltages measured are very similar, that probably means that the LED strip is open circuit (could also be  PSU failure, but unlikely). If the voltage is zero then it means PSU failed, LED strip is shorted or it could be a fuse (I see a fuse in the picture, presumably for backlight power output, small rectangular soldered on the board).

Hope this helps to get started, but be careful of high voltages and don't harm yourself. Backlight voltage could be quite high, not to mention the main bulk capacitor of the PSU.
 


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