XBR-75X940D array backlight works but LCD panel shows no picture
With a video input, I can see the array backlight move with the picture, but the LCD screen itself is black. Even on-screen menus don’t appear - the LCD is not functional.
There are three boards in the signal path - the main board (BM1), the DPS board, and the Timing Control board. The fact that the backlight is active with video input suggests that the main board is fine, though the speakers don’t seem to work which suggests that it may not be.
The DPS board sits between the main board and both the Timing Control board and the array backlight control board. I can find very little information on how to diagnose it.
The Timing Control board has 12.6V at its power connector and the on-board fuse is fine. I have confirmed that the panel is not shorted.
The links between each board are high speed digital, and I don’t have a logic analyzer. I’m not sure how to go about narrowing it down to which of the three boards warrants replacement.
Cette question est-elle utile ?