Hello, everybody!
I have the same problem with my Toshiba satellite a60. When I try to boot from hard drive, I only get the "_" sign blinking in upper left corner. I can normally access BIOS and boot from CD/DVD. Installation of Windows XP goes normally till the first rebooting (all checks, formating hard drive, copying files to HDD), but when it comes to booting from HDD, again I only get the "_".
Toshiba satellite a60/65 is known for its overheating issue. I thought that maybe problem is CPU overheating, so I changed a thermal paste on CPU, but that didn't solve my problem...