TV won’t turn on. No stand by light.

Looking for any help with my TV. It’s a Samsung UN65MU6500FXZA. Issue started this past Saturday. Was watching the news during a bad storm and our power was knocked out for 6-7 hours (tv was plugged into a surge protector). When I tried to turn the tv back on, it would not power on. I tried all the basic troubleshooting tips. I checked the outlets, tried a different outlet, checked that the power cord was still working. I then took the back cover off to look at the boards. I could not find any visible damage to either board (no burn marks, no puffy capacitors). Fuse is ceramic so I couldn’t see if it had blown or not. Decided to replace the power board. After replacing it, I still had nothing. I verified that the TV was in fact getting power, because when I disconnected the power board from the main board, the backlight came

on. But once it was plugged back into the main board, there was nothing. So I figured the main board had gone bad. So I bought a new main board, and replaced it. Tried to turn it on and still nothing. I’m now at a loss of what to try next. Any help is appreciated. Thanks.