Samsung 75" QN90A Neo Qled 4K TV - No Picture, No sound, Keeps Restarting, Flashing LED, Repair

I have a 75" Samsung QLED ( QN75QN90AAF ) that had no picture, no backlights or sound. When I turned it on, all I could hear was a relay clicking and the red led on the front panel would flash a few times. After taking it apart, I was able to isolate the problem to the main board. I could not find a bad component and reflowing the graphics processor with a hot air machine did not help. I ended up purchasing a replacement board and that got the tv working again. Big thanks to Patch1stripe TV Parts for his guide on taking the TV apart. HOW TO REMOVE A SCREW-LESS BACK FROM A SAMSUNG TV    • HOW TO REMOVE A SCREW-LESS BACK FROM A SAM...   I was able to find a replacement main board from tvpartstoday.com BN94-17601H Samsung Main Board https://tvpartstoday.com/products/bn9... I'm not sure why the tv failed in the first place. The tv belonged to my neighbor and they had it for only two years. She said they tried to turn it on one day and nothing happened. Hopefully the new board will keep this Samsung QN90A working for awhile because it really has a beautiful picture.