Samsung 173S LCD monitor is dark
I had the same problem.
I opened the unit and checked all the caps- None were bloated or obviously in trouble. I checked the voltages on the two regulators on the green vga proccessor board. They should be 2.5 v out on the left on and 3.3 volts out on the right one and the input to the board is 5.1v from the main powersupply. The Power supply also supplies 12.4 v to the inverter for the backlight power.
These were all good.
I checked all these for reference for benifit of others. I expected the problem to be the video input/connector/opens related because without the cable connected the monitor functions thus the voltages should be good and the cpu/brains should also be OK.
Either the unit didn't detect the vga signal or was being forced into standby by some means.
After dissaembling the unit the monitor begain to function again, and then wouldn't after I reinstalled into the case agian.
I then found that the VGA board would work/not work with a slight flexing/warping of the board. The mounting screws and two clips bend the board when it is normally in place. I was able to listen closely to the vga proccessor board as I flexed it an could hear the pins on the Main Chip crackle. I looked very closely with a magnifing glass and could see that the pins on the side toward the VGA connector were loose- probably this batch of boards had a poor solder proccess and the connections were faulty.
I reflowed the solder on the main chip on the side toward the vga connector. Be VERY VERY careful these a extremely small pins. Have "good" solder wick available for the removal of blobs.
The Monitor now is again working and flexing the vga board no longer affects the operation of the unit
Jul 08, 2007 |
Samsung SyncMaster 173S (Black) 17 in....