Repairing Samsung 713N LCD Monitor with SE7889-LF Ic Problem.
This Samsung 713N LCD monitor came in with no display symptom and no power. In other words, once you switched ‘on’ you could see the power LED lights up (no display) and then for couples of seconds the power led light goes off. When I removed the signal cable and switched ‘on’, now I could see the check signal cable OSD appeared at the screen. This proved that the inverter board, lamp and power supply is working. Again, I plugged in the signal cable, the display and power LED light went off.
After opened up the cover, I check the on/off signal from the mainboard to the inverter board. With signal cable in, there was no on/off signal to the inverter board but when the signal cable was disconnected, you could see clearly from your meter there is a on/off signal going into the inverter board thus the display appeared with the check signal OSD present at the display. From this test, it is very obvious is the main board problem.
To confirm whether is the main board problem, you have to use a similar Samsung 713N model to confirm it. True enough, after substitution with a known good board, the monitor is okay. So now we can confirm is the mainboard faulty. The real problem now is at where we can find this board or the suspected part number SE7889-LF ic for replacement? Checking the components surrounding the SE7889 ic yield no result.
As mentioned in previous articles, to troubleshoot LCD monitor is easy but to get the part is a little bit difficult. Samsung don’t sell you the mainboard, if you send to them for repair, they will charge a very high price which is not worth to repair.
As I’m writing this article, I still could not locate the suspected ic, but if I found it I will let you all know. Samsung 510bn lcd monitor also have this kind of problem which is the mainboard spoilt.
Although in this article I could not pinpoint to you the exact faulty component, at least you would use my procedure to confirm which board is giving problem. In other words, whether you are troubleshooting the Samsung 713N LCD monitor or other brand, the testing method is the same.