Alarm Beeps on Booting up on S5520HC Motherboard.

 Service Guide for the board has some info that may be helpful.

 

If it is booting and you are not getting a status LED yellow or flashing, Most likly you are hearing the USB device discovery.

Beeps once quickly for each USB device it finds.including the internal hubs and devices. 4 is abot normal. My system has a lot of extra USB devices addded and sounds like PONG during POST.