Re: Samsung Syncmaster 931BW - No Power
2 more thing I tried.
1. I went to the troubleshooting no video step (analogical one) and skipped the tests required an oscilloscope to the step checking the voltage on CN400 (the connector that goes from the logic board to the LCD), and there was no 5V on pin 1,2 and 3. Following that I tested the PANEL_EN and BL_EN signal (they should High and Low for ON), and both of them were Low (the PANEL_EN one was 0.6V).
I also tried testing the digital troubleshooting part, since it revers to the same 1,2,3 pins for 5V,...
aliens
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Last Activity: 11-25-2011, 01:01 PM
Joined: 11-23-2011
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Re: Samsung Syncmaster 931BW - No Power
Could the problem be one of the other caps I haven't replaced? They look ok but I guess that can still be misleading.Leave a comment:
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Re: Samsung Syncmaster 931BW - No Power
I can confirm that. The button is connected to 1.8V, which goes to 0V when I press the button (but pin 9 doesn't change from it's value of 0.141V, so it still doesn't seem to request back lights)....Leave a comment:
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Re: Samsung Syncmaster 931BW - No Power
As seen in the picture (from left to right):
IC602: 3.8V 1.8V 0V and 1.8V on the bottom
IC601: 5.15V 3.3V 0V and 3.3V on the bottom...Leave a comment:
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Re: Samsung Syncmaster 931BW - No Power
After a bit more testing, the 5V on pin 6&7 and 15V on pin 2 are solid (no fluctuations). On pin 9 there's 0.141V constantly. Next to it it says On/Off, and the manual says that On is 0V (but as I mentioned, it says that during testing it should be 5V)....Leave a comment:
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Re: Samsung Syncmaster 931BW - No Power
Here's the PDF that includes the "No Power" troubleshooting guide....Leave a comment:
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Re: Samsung Syncmaster 931BW - No Power
I'm not home right now to make a print of the troubleshooting page of the manual (but you can see it in pdf 931C[7] from the service manual archive I linked in one of my previous posts), but in it it states that, on CN600 (the connector on the logic board that connects to the IP board), pin 2 should be 15V, pin 7,9 should be 5V. My tests show 15V on pin 2, 5V on pin 7 (and 6), but 0V on pin 9.
The second picture attached in my previous post shows this (although that is the IP board)....Leave a comment:
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Re: Samsung Syncmaster 931BW - No Power
One thing though, the service manual (pdf 7) says I should have 5V on the 9th pin on the ip board -> logic board connectors, yet somewhere else it says that 0V should be for the ON status. I have 0V as well, (though as I mentioned, I do have 15V on pin 2 and 5V on pin 6 and 7). Would this be an issue?Leave a comment:
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Re: Samsung Syncmaster 931BW - No Power
Tried all combinations, no joy. I noticed that, when the monitor is plugged in, there's a very faint voltage sound coming from the ipboard/logic board. When I press the menu/brightness/etc buttons the sound slightly shifts higher or lower, which I guess it means that the buttons should be working, yet there's still no(t enough?) power.
Cheers...Leave a comment:
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Re: Samsung Syncmaster 931BW - No Power
Here are some pics. First is the whole assembly ip board -> main board -> function PCB/power button. The following are the ip board, main board and function pcb with measurements done as Glennjamin did. Last is with the bad caps I replaced.
I also found the service manual here:
[url]http://www.givemefile.net/smanuals/monitors/samsung/file/37458.html[/url]Re: Samsung Syncmaster 931BW - No Po... board -> main...Leave a comment:
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Re: Samsung Syncmaster 931BW - No Power
Hey,
I have a very similar problem as Glennjamin, only it's with a 931C instead of 931BW. The electric boards are 99% the same.
My problem started with slow starts, led button flickering for like 10 minutes (longer if I system was shut down over night) before starting up. My bad was not fixing the issue right away, and instead I waited like 2 months until a few days ago, when the led button wouldn't light up at all, as it would be unplugged. I opened it, replaced the bad caps (2 820u and 1 470u), which would probably...Leave a comment:
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