I'm trying to repair this notebook. It only boots to BIOS. I have been able to update the BIOS from a thumb drive. I have run Passmark memtest and no problems there. However, it will not boot to DOS on a USB stick which I know works because it works on other computers. Does not work using boot override either. I'm trying to decide if it's the mobo or the hard drive that is bad, so I'm looking for a way to test the hard drive given the above limitations. Thanks for any assistance.