Tcl 50 does not display image. backlight turns on, white light on the bottom turns on.

If you're unable to change the backlight brightness on your TCL Roku TV and the backlight remains on even when the LCD screen is turned off, there may be an issue with the TV's firmware or hardware. Here are a few things you can try:

1. Reset the TV: Sometimes resetting the TV to its default settings can fix issues like this. To reset your TCL Roku TV, go to Settings > System > Advanced System Settings > Factory Reset. Note that this will erase all your settings and preferences, so you'll need to set them up again.
2. Check for updates: Make sure your TV's firmware is up to date. Go to Settings > System > System update and check for updates. If there's an update available, download and install it.
3. Check the cables: Make sure all the cables connected to your TV are securely plugged in. If the backlight issue started after you took the TV apart, it's possible that a cable came loose or wasn't plugged in correctly.
4. Contact TCL support: If none of these steps work, it's possible that there's a hardware issue with your TV. Contact TCL support for assistance or consider taking the TV to a repair shop.

The issue you're describing with your TCL 55-inch QLED Smart TV, model U55X9006, where you can hear audio but the screen is black, could be caused by a problem with the backlight or the backlight driver.
Here are some steps you can try to troubleshoot the problem:

1. Check the backlight settings: Make sure that the backlight settings on the TV are set correctly and that the backlight is not turned off.
2. Check the backlight driver: The backlight driver is responsible for controlling the backlight, so check that it is functioning properly.
3. Check the backlight inverter: The backlight inverter is responsible for providing power to the backlight, so check that it is functioning properly.
4. Check the video signal cable: Make sure that the video signal cable is securely connected and that there are no damaged or loose wires.
5. Check the T-con board: The T-con board is responsible for controlling the video signal, so check that it is functioning properly.
6. Inspect the screen: Check the screen for any visible damage.
7. Contact TCL customer service: If the above steps did not resolve the problem, it is best to contact TCL customer service for further assistance and repair options.

That is usually a sign that the power supply or the LED's in the display are failing. You may be able to order new power supply or parts for it from shopjimmy.com

Doing the flashlight into screen test and seeing a faint picture indicates the backlights are not working!

There are only two things that would cause this:
1) led backlights blown!
2) T-con board faulty!

This is a backlight failure, either the T-con board or led backlights, without further testing it will be a guess.

Information for advanced users.
The absence of an image in the presence of a signal is often caused by a malfunction of the display backlight. Moreover, the problem can be both inside the LCD panel (matrix), for example, a malfunction of the LEDs( LED), and outside in their power source - the LED driver.
Without the backlight, you can sometimes see a barely noticeable image with a certain successful hit of external lighting on the screen.

Contact any service technician.
http://electronicshelponline.blogspot.com/
http://schematicscom.blogspot.com/
http://homenol.blogspot.com/

It may be the internal backlight that is failing. You can take a flashlight and hold it close to the screen, move the flashlight all around the screen and check if you can see anything. The display will be dark, but you should be able to make out the image that is there with the flashlight technique. If you can see an image on-screen, then your backlight has failed and you will need to replace the monitor. Weather or not you see an image is not a critical issue, but a tool to verify if the backlight is off or some other issue is causing the problem.
Note, it may be difficult to detect an image on the un-light display, for example if you have a dark image as your desktop background. So make sure to fully scan your display (top to bottom, and left to right covering the entire screen) with the flashlight technique in order to see any image on-screen.

hi

ther is only 1 option for this unit

http://www.uniden.com/pdf/BC72XLTom.pdf
page 50

-Using the Display Backlight-
To turn on the display light for easy viewing at night, press . The display lights for 15 seconds. To turn off the light sooner, press again.

other models have more options but this one doesnt

same for the 92xlt

D