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My tv keeps blinking on and off. How to fix? It's not the power supply

My tv keeps blinking on and off. How to fix? It's not the power supply

My Lg47lb5900 tv keeps blinking on and off. It's not the power supply. Any other suggestions? It's only 2 yrs okd

Asked by: Guest | Views: 354
Total answers/comments: 7
bert [Entry]

@rburke26 if your screen does something in spite of the new power board which includes the backlight circuitry like this there will be an error with the LED backlight strips themselves. These are replaceable but it is not easy since you will have to dismantle the panel. Post your panel number, not the TV's model number so we can try to find the right strips for you. The numbers are usually on a label fixed to the panel.
bert [Entry]

You said it is not the power supply. Does that mean you have taken the back off? Is the power supply built in or is it external, like a tablet 19 volt transformer? If you have opened the TV unit, can you identify a relay that clicks as it powers on? If so, as it powers on, hold a small rare earth magnet near the relay. BE CAREFUL not to touch anything, let the magnet stick to anything, hold it near any integrated circuit chips, etc. Sometimes the coil inside the relay gets weak. Holding a magnet NEAR the relay, (but not touching anything) can boost the magnetic field which operates the relay, allowing the contactor inside the relay to close (make connection) and the unit will remain on even after the magnet is taken away. If that works, the relay is bad.
bert [Entry]

"Electronic circuits the tend to draw the most current, will run hotter, and heat degrades electronics, so when shooting trouble, It makes the most sense to start with those item. In LED flat screens, its the LED back light panel.

Best way I have found to diagnose a back light problem is to place the Tv in a very dark room, and turn it on in the set up menu, and using a bright flash light pointed at the screen, and see if one can observe the setup screen.

It will be very dim, but you will be able to make out the text, or something. This is the Flash Light test. This means that that the information IS being sent to the display. The LED back light which is not working, allows the signal to the display to be viewed, in normal operation.

As mentioned elsewhere, the LED back lights are LEDs mounted in a strip. which each strip draws a good amount of DC Current,which is why a flat screen feels warm to the touch when operating.

Changing the LED back light strips involves disassembling the many layers of the flat screen, not an operation for the faint of heart ! In that one has to be careful that the display isn’t damaged in the disassembly process, and needs to be preformed in a very Clean environment as any dust/ stuff that gets trapped between the layers will be visible all the time the display is on, assuming your successful getting it to light up again.

With the sell price of new flat screens tv coming down, ( 32 in 720 P Insignia Brand At Walmart on line this morning is $89.00.{12_29_2018}. The repair shop has no way to a descent hourly way to pay him self, which is why I left the field in 1978.!!

If the dead flat screen is not your main go to Tv, & have a place where one can leave a flat screen disassembled for the long periods of time for the container ship to come from China to Long Beach Ca., and you work for free, then !&&* yeah give your best shot. You Tube videos are your BEST friend.

In my experience with no display / black screen, its the LED driver electronics.

Just my 3¢. g²"
bert [Entry]

Com on people power supply is rarely an issue in LCD or LED unit!! I guarantee it it Main board
bert [Entry]

I just had this problem on and off continuously I took the batterys out both of my remote that are tuned into the TV and it solved the problem
bert [Entry]

It was the HDMI cable that caused my TV to flicker try replacing it first
Ppdgcx [Entry]

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