Hi,
I having some trouble fixing a PSU fault on a TV. Basically the backlight would come on for 10 seconds or so and then shut off and I saw the voltage drop. On further inspection I found 2 burnt out led's on one of the 2 strips and replaced. The same fault still existed but I couldn't measure anything obviously wrong. Each string was roughly 35v and two in series was 70v tested fine with the LED tester. I went to replace the MP3394s but the board popped so I bought another board off Ebay as close as I could find. This time the tv powered up fine but still no backlight at all this time. I assumed it was a duff board. Then I looked at the specs of the MP3394s and read the max output is 55v?. I had a spare LED array kicking around that worked at around 30v so as a test plunked that on and reset the power and it came on and was stable. Following the tracks the LED driver outputs on both boards look like the are all in parallel, what am I missing here?
I having some trouble fixing a PSU fault on a TV. Basically the backlight would come on for 10 seconds or so and then shut off and I saw the voltage drop. On further inspection I found 2 burnt out led's on one of the 2 strips and replaced. The same fault still existed but I couldn't measure anything obviously wrong. Each string was roughly 35v and two in series was 70v tested fine with the LED tester. I went to replace the MP3394s but the board popped so I bought another board off Ebay as close as I could find. This time the tv powered up fine but still no backlight at all this time. I assumed it was a duff board. Then I looked at the specs of the MP3394s and read the max output is 55v?. I had a spare LED array kicking around that worked at around 30v so as a test plunked that on and reset the power and it came on and was stable. Following the tracks the LED driver outputs on both boards look like the are all in parallel, what am I missing here?
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