Hi can anyone help I've been trying to fix my pc and I've bought an old am3+ motherboard but when I load the pc it says reboot and select proper boot device, I've made sure the boot priority is correct, I've tried removing cmos battery and I've tried booting from a USB. When I try from USB it doesn't say reboot and select proper boot device it's just a flashing underscore and nothing happens, the motherboard doesn't have uefi, the version is the latest version so I don't think flashing will change anything. The motherboard is M5A78L-M/USB3. I'm using ssd to boot from, thanks to anyone who can help