Toshiba Equium A210-1AS Boot problem

My daughter has a Toshiba Equium A210-1AS laptop and has encountered a problem that prevents the 'boot-up' process getting much past the BIOS screen (AMD Phoenix). After the initial 'splash' screen for Toshiba, the POST signals seem to be three short, space, three short, space, repeated short beeps. I have re-affirmed the Boot sequence from HDD using F12 but the screen goes blank with just a flashing cursor in the top left corner of the screen.
I believe the initial 3 beeps sequence indicated RAM problems so I have done the usual remedy by removing RAM sticks, changing position, and replacing with known good sticks but the same end result. The HHD seems to be being accessed (per disk accessing indicator at front edge of laptop) but never loads to Windows 7. The HDD seems to be good but I am stuck. I have tried just about everything to get the kit to boot to Windows but it never gets past the flashing cursor in the topleft - its as if everything has frozen up. Anybody any ideas?:confused