There's two possibilities here:
1) There's some device, peripheral, or piece of hardware, that is causing POST to hang on boot at the AMI BIOS screen, or
2) What you are seeing, is really a fail-safe boot screen, because the BIOS has been corrupted.
If it's 1, try removing everything non-essential, try different sticks of RAM, different video cards, different PSUs.
If it's 2, then look up in the manual or on the mfg's web site, EXACTLY how to perform an "emergency flash recovery". You may not just have to put the BIOS on a flash drive, you may have to make sure it's formatted a specific way, and the file is named something specific, like BIOS.BIN or AMIBIOS.BIN, or maybe the model of the mobo, with a specific extension. You would have to look that up.
There's actually possibility number 3:
3) The mobo is hosed, and should be replaced entirely, and then safely disposed of.
If you're getting some semblance of POST, though, that seems less likely than the other two possibilities.