Got a Asus P7P55 LX MB, getting "Scanning Devices message, Please Wait.." and seems to hang there. I can't get into the BIOS. Anyone experience this ? Is this MB issue ? Any suggestions would be greatly appreciated.
Make sure all the components are properly plugged in and powered, remove the battery for about 15 mins, reinsert it and try again.
If still no dice, unplug all components but the essential ones (HDD, 1 stick of RAM, CD drive) and try again.
If you have them (and I think you should have them), then you can remove the correct side cover of the PC case and look at the motherboard. One of the LEDs should be shining bright red. Depending on which LED is shining red, you can take corrective action.
In most of the cases, corrective action is to reseat the troublesome card or RAM stick or to press the mem-OK button. Your motherboard manual may come handy.