The display is lit but the image is not displayed

I decided to check the screen from another set-top box, the backlight came on, a dark screen. I decided to put it back into the board in the work console, but the screen does not work, only the backlight. I disassembled, saw bent contacts on the connector. I bought a new one, there is no image soldered. What could have gone wrong?

I changed the connector of the screen, but there is no image.

probably bad soldering on the connecter.

Disconnect battery/power and put slight pressure on each of the pins touching the pads and see if it wiggles or is floating.

I soldered it well, checked it with a tester and examined it under a microscope. Perhaps when the leg bent in the old connector, it made a short one and burned the display or some other detail on the board. I examined the board and checked it with a tester, there is no short circuit. Only the backlight is on. Need a display pinout to check all signals?


I’d take diode or resistance readings on connector pads and compare to a known good board, maybe somethings open or short.

Did you check the inductors? that is if they’re populated on your rev board

I checked the capacitors and diodes for a short circuit, I also checked the power supply from the 8316 microcircuit, the power supply is 5.4v and -5.4v. What kind of coils to check?

@Calvin has posted diode readings for this connector, so I’d suggest looking at his posts, finding the diagram and comparing results.

The multiple inductors are just above the connector when looking at it ribbon entry side, they’re hard to miss and look similar to the ones below P13 IC, though as i say, some board revs don’t populate them and instead bridge over on traces

Please give a link where it is published. There are no coils in my board, but comes directly from the processor


1 Like

The values ​​all agree that by bending the contact on the connector, I burned the display, not the board?

possibly… Only one way to know for sure and thats to test with a known good LCD or test the suspected bad LCD with a known good board

I ordered the screen, I’ll take it and try to connect it

There is an IC to the left of the LCD connector that I’ve had to swap out on a board with a similar issue. I think it provides power to drive the LCD. Might be worth investigating that if you are sure your ribbon connector is good. I’ve not investigated it in detail so others on this forum may be able to provide additional detail.

I bought a new screen and there is an image.

1 Like