I have a Vizio M261VP 26" LED/LCD HDTV that will turn on/off and has sound but no video. The LED backlight lights bright and then dims to about half the brightness after 5-10 seconds. There is no video and I can not see the menu when selected.
The TV is powered from a 19Vdc AC/DC Adapter that checks ok.
There are basically only 2 boards in this tv. See attached pictures. The main board part number is 3626-0082-0150(3E)). It contains all power supply circuitry (including for the LED Backlight), audio circuits, video circuits, and all external input ports. The second board is the "t-con" display board. It looks like Vizio uses an LG display assembly part number 6870S-1103A. The "t-con" display board seems to be and integral part of the LG display assembly. There is also a small wireless daughter board for wireless connection to a network.
I checked the 3 obvious fuses, and I have checked the voltages at various points on the main board/display board and they appear to be normal. I looked for swollen caps and any other damage, but everything looks ok.
There is a 10 pin ribbon cable on the upper right of the main board that connects to the upper right of the LCD. I think this is the LED backlight cable. Voltages in the upper right area are around 108Vdc on the Power MOFET and Schottky Diode. Should I assume the backlight is ok since it turns on with the power? Is the dimming normal after 10 seconds?
From the symptoms is there any clue where the problem may be i.e. main board or t-con display board? Is there any test that can isolate it to which board has the problem and where on the board to look?
Any help on where to go from here would be appreciated.
The TV is powered from a 19Vdc AC/DC Adapter that checks ok.
There are basically only 2 boards in this tv. See attached pictures. The main board part number is 3626-0082-0150(3E)). It contains all power supply circuitry (including for the LED Backlight), audio circuits, video circuits, and all external input ports. The second board is the "t-con" display board. It looks like Vizio uses an LG display assembly part number 6870S-1103A. The "t-con" display board seems to be and integral part of the LG display assembly. There is also a small wireless daughter board for wireless connection to a network.
I checked the 3 obvious fuses, and I have checked the voltages at various points on the main board/display board and they appear to be normal. I looked for swollen caps and any other damage, but everything looks ok.
There is a 10 pin ribbon cable on the upper right of the main board that connects to the upper right of the LCD. I think this is the LED backlight cable. Voltages in the upper right area are around 108Vdc on the Power MOFET and Schottky Diode. Should I assume the backlight is ok since it turns on with the power? Is the dimming normal after 10 seconds?
From the symptoms is there any clue where the problem may be i.e. main board or t-con display board? Is there any test that can isolate it to which board has the problem and where on the board to look?
Any help on where to go from here would be appreciated.
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