The damage to the lcd logic board will cause the lcd screen not to display the image properly, there are intermittent color lines in the vertical direction of the screen, there are no characters, of course, there is no menu display, but key board and remote control can also work.
Unlike the blurred screen produced by the LCD itself, the blurred screen caused by the failure of the lcd logic board shows a regular blurred screen up and down, which can be confirmed by changing the signal source or changing the 4:3 mode.
Logic board maintenance ideas:
1) check whether the vulnerable components such as IC and filter capacitor of the main chip are obviously blackened or the color is abnormal, etc.
2) to test whether the short circuit resistance of each power supply test point is reduced, and whether the insurance is open or not.
3) to test whether the power of each power supply test point is normal, that is, the power supply Vcc---5V/12V, main chip-3.3V, 2.5v, 1.8V, 1.2V, etc., VAA---14V,VGH--- about 26V, ~ VGL Mustang, about minus 6V mae, 4VREFcomm, about 6V, 5V, 5V, 5V, 5V, 5V, 5V, 5V, 5V, 5V, 5V, 5v, etc.).
4) Test whether there is any defect in the data exchange between the LVDS DDR and the main chip.
5) check the arrangement and insertion of each connecting cable.
Whether it is a blurred screen or a white screen, if it is confirmed that the logic board is broken, the maintenance idea: whether the 5V to 3.3V stabilizer block (AIC1084) of the drive board has a power supply output. "screen body drive plate fuse (F)-3.3V" DC-DC conversion circuit "negative pressure forms IC (- 7V)" row, column drive IC.