Antwoord op "How to be sure I need new backlights"My TV looks like the one above, it is Vizio E70-E3. The 12 LED backlight strips appear to be controlled in sections of three Strips (each strip is 10 LEDs of 3V DC apiece). The pic above shows the lower right quadrant failing (one section of three strips). On my TV it was lower right and then a month later the top right also went dim. Important - the dimmer strips appear to be working still, but they are just dimmer. If I use the "backlight" adjustment I can see them working but they remain about 50% DIMMER than the rest of the TV. When I look at the main power board I see there are 4 LED voltage control outputs (indicating four sections as I said). But what I can't determine is whether it is the LED strips or the power board which is bad, or maybe even the T-Com board. It has been really hard to find information ion this specific problem online. just now by Paul Motter
Antwoord op "Vizio m55-D0 dark corner - Backlight?"I have the same problem. I know a little. I see the power board has 4 separate voltage feeds to handle 12 LED strips (so each one handles three strips of 10 LEDs just like yours, I have an even number of LEDs that have turned off (I have six strips off all-together and they are the upper left corner and the lower right corner - so it looks like the power supplies are failing, more so than the LED strips, although it could be either. Generally, LEDs do not die unless they get too much voltage. Mine appear to be still working because I cab dim them, but I can’t make them bright enough anymore. I can pretty much tell the full strips are the same. So, my inclination is to test the power supply board first. You take a voltmeter and put - to ground and put + to the voltage send (#2,3,4 or 5) on the ribbon cable. A good one should read no more than 30v DC. If this does not work put three 9v batteries in series (total current = over 27V DC) and go to the LED strips and see if you can light them with the batteries....