I have a weird problem with my BIOSTAR A760G, but don't know what causes it.
On first boot keyboard and mouse do not work and anything connected to usb. After reboot by pressing the button everything is normal again. It's acting like there is no power in usb, for example led on usb just short blinks for a second.
Tried disabling SATA and IDE disks in BIOS, first SATA then IDE, problem reappears only when computer is powered off for a longer time.
I have changed also my powered supply Mercury 500W (24pin) and replaced it with Fortron 350 W which is 20 pin (I don't use PCI-E card, just integrated HD3000). Same thing. Tried to clear NVRAM, set SATA to AHCI, nothing. I don't know if those extra 4pins on 500 W PSU can cause a malfunction. I have spotted two capacitors as seen on picture. They seem to be a little bit inflated. http://ompldr.org/vaDE1NA
I used this PSU in previous configuration with K8N board and everything was fine. But that board had 20 pin connector, so 4pin was not necessary.
I have separate com port connected, can this cause the problem?