Sep 27, 2022, 5:44 PM
Post #1 of 3
I have been trying to repair this TV, and have had great success replacing boards on other TV's but this one is not cooperating, and I am trying to figure out if it is beyond repair. When I plug it in, the backlight comes on, then 3 sec later the TV powers off, then 3 sec later comes on. When it comes on, I only get the faint blue screen from the backlight. If I unplug the cable from power board to main board, the backlights remain on, and it does not power cycle. I tested voltage on the power board and did not get the 13V, so I replaced the power board which did not fix. Then I replaced the main board, and this did not fix.
Samsung QN75Q6DRAF power cycling on/off
Then I found a video suggesting that one of the flat ribbon cables from main board to display could have a short, so I followed the video and put a small piece of masking tape over several of the terminals on the ribbon cable, and this enabled the TV to power on, and I got a full picture, however, there were 2 vertical lines in the center of the picture, which I thought was due to a bad ribbon cable, so I replaced it, but now without the masking tape, it went back to powering on/off. If I unplug the ribbon cable, it no longer power cycles. Only thing I can think of is there is something wrong with the LED board that the ribbon cable connects to, but then why would I get a full picture when masking several of the terminals on the ribbon?
Anyone have any ideas on what I can try next, or is this a lost cause? I have some photos but not sure how to upload them.