Samsung 760VTFT LCD Monitor Repair In Progress

This unit was experiencing the common symptom of screen going black after a few seconds of turn on. Turn off and on again, problem would repeat, but things got better with some dark splotches on successive cycles of turning off and on until after about 2 minutes, the screen would stay on properly and then work fine thereafter.

I disassembled the unit and on the power board I found possible sources of the problem. There was a film capacitor (C11) pushed up against and in contact with the heat sink on a transistor (only heat sink on the board). It was brown in color, but on further inspection, the original color was bright red, the brown discoloration may have been due to heat or leak through. Additionally, the power mosfet MTP23 was leaking a brown substance from the lead end onto the board. All the electrolytics tested fine with my esr meter and also looked fine.

The "Display Type" is GH17MS with a "Model Code" GH17VSSN. The power board was designated GH15/17 Rev 3.0. The value of C11 is unreadable. How would I got about finding the value of this capacitor?

Reply to
Rob
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OK, I found a board that appears to be identical to mine here:

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The bad mosfet is in the upper part of the board just to the right of the bank of six capacitors, you can make out a corner of it behind the white ribbon cable. The mysterious capacitor C11 cannot be seen, it is adjacent to the heat sink on the side of the mosfet. There is another similar film cap, but it is too far from the heatsink to make contact with it.

Reply to
Rob

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