How do you know if your motherboard is fried. Everything looks ok. But the problem may not be visible. Are their visual signs I can look for to determine if I am working with a burnt out motherboard, or am I still working with a bad PSU?
Sometimes you can look at a board and see it is fried by it's capacitors. If they are swollen or leaking, that is a sign that your board is toast. But most of the time you can not just look at a board and tell that there is something wrong with it.
All you can do is troubleshoot your system, one part at a time.
If you need further help, I'd recommend you continue to post in your other thread, and not start new ones. It just confused things.