Try all repairs and troubleshooting at your own risk.
In this video we will show how to test and LED TV that has no backlights and determine
if the backlight problem is being caused by the power board or the LED strips.
The first step, if you have no image on the screen is to determine if the TV has backlights
that are working or not.
The easiest way to see if the backlights are working is to look through the back cover
of the TV and plug the TV in and turn the TV on, and see if there is any light coming
through the back.
This can be difficult sometimes and it may help to turn the lights off to see if there
is any light coming through.
If you cannot see any light coming through the back cover, then I would recommend removing
the back cover.
There should be holes in the back panel which is underneath the back cover.
Once you have powered on the TV to check if there is light coming through the holes, it
will help to turn all of the lights off in the room to give you the best chance to see
the light coming through.
If you do not see any light coming through those holes, then it would appear that your
TV backlights are not working.
If your LED TV does not have backlights, the problem is most likely either with the board
that controls the LED strips or the LED strips themselves.
There are a few ways to troubleshoot the symptom of no backlights.
One way to troubleshoot is to find the board that connects to the cables that connect to
the LED strips.
If you know what the voltages are supposed to be on that board, then you can do the following.
Plug in and turn on the TV.
Then check the voltages at the LED strip cable connections.
Test each pin and take note of the voltages present.
If the voltages are correct, then the board seems to be working fine and the LED strips
are most likely the problem and should be replaced.
If the voltages are at Zero or less than what they should be, then the problem could be
with the board or the LED strips.
You can troubleshoot further by unplugging the TV, disconnecting the cables and then
plugging back in the TV and checking for voltages on the board.
Be aware that if voltages show as zero, the TV could be protecting itself.
Sometimes when there is no load on a connection, the TV will stop outputting voltages to the
backlights to prevent damage.
Once again testing voltages on the board can only work if you know what the voltages are
supposed to be, when they are good.
Therefore the only way that we recommend to know for sure if the problem is the power
board or the LED strips, is to disconnect the LED strip connections and test them individually
using our LED tester.
The LED strip tester separates the power supply, so that you can test the strips alone and
know if they are good or not.
Connect the negative lead to the negative connection and the positive to the positive
connection.
The LED tester will automatically gauge the correct voltage to send to the strips to turn
them on.
You should start to see some light coming through the holes on your back panel.
If you do not see any light, try turning off the lights in the room to be sure.
It can be helpful, since you are testing this to have maybe an extra person to turn the
lights on and off, while you are doing the testing.
If you are one hundred percent sure that there is no light coming through the holes, then
the problem is most likely with the LED strips and they should be replaced.
If you are seeing light coming through the panel when you test the LED strips, then the
LED strips are most likely working and the problem is with the board and the board should
be replaced.
In order to determine why your TV has no backlights, the LED tester is a great way to determine
if it is either the board causing that or the LED strips.
The LED tester can also be used to test individual strips of LEDs, as well as individual LEDs
on a strip.
You can find more information about the LED tester in the description by clicking the
link or by clicking an annotation on the screen.