LG 47LB5900-UV TV display is flashing / flickering on and off
I have a LG TV 47LB5900-UV, which is about 1.5 years old and the screen suddenly started flickering on an off. I was watching TV on it and suddenly the display just went off, the flashed on then back off. At this point the display is primarily off, but flashes on for half a second, then back off. This is happening with the initial screen, on screen menu, and with any input. I opened the back and reseated the internal cables between the 3 boards, but the issue remains. The connectors on each cable are somewhat recessed, so I am not sure of a good way to clean them.
It sounds to me like you have a bad power supply board. Some component on it has gone bad either a cap, resistor, diode, or even a fuse. There are various components on the board that need to be tested. If you are familiar with soldering and desoldering, then go ahead and remove each piece and perform and ohm test as well as resistence test. Check relays as well. Most of the time one or more components on the HOT side of the board go bad. This can be time consuming so I find it easier to simply replace the entire board.
Hi You will find that a few of the leds have blown and taken out the power board , you will need a new PCB and new leds mines had exactly the same problem after two years running, i put it in the bin to save a lot of heartache cause if you get it repaired it will almost certainly happen again unless you can turn the backlights down , incidentally out of all the lcd televisions i have had its only the lg smart tv that has let me down after such a short time
I had this problem and I found that an LED had caused the problem. Instead of replacing the single bad LED's [there were two] I chose to replace the strips containing the bad ones. I will tell you if you decide to do this job yourself BE CAREFUL with the main screen if you crack it, might as well toss it, it will be cheaper to buy a new one. Hope this helps!
Easiest way to see if you have a backlight problem on your flickering tv is to shine a torch at the screen while pressing the volume button. If you can see a image on the screen then your backlights have failed.