Hello, I have a 75 inch Samsung Smart TV that I purchased around mid-2014. We were watching TV when it suddenly went off. No Sound. The Infrared light responds when you press any button, but nothing happens. I can't see any light from the screen and there is no sound. Pressing Menu does not bring up any screens. I have a minor amount of skill in electronics and comfortable with replacing parts.
From what I have read on forums it was suggested the issue was the main powerboard. I ordered and replaced the board with a used board but the TV still will not come on. I would appreciate it if anyone in this community could respond with suggestions on how to troubleshoot and or what part to replace. As the replacement board is used, it's possible the board was dead on arrival. Is there a way to test the mainboard?