This is one I've never seen before and I'm hoping someone can help. I was a computer support person for over 20 years and am now retired.
The machine in question has been in operation for about a year. No changes have been made to the hardware. At power on it runs POST OK, counts memory correctly, and detects the drives. At the point where it should start to boot it stops with a blank screen. There are no error messages. We can get into the BIOS setup and set it to boot from a CD. Same problem; no error messages. The CD is standard IDE and the hard drive is SATA. There is no floppy drive installed. Everything in the BIOS looks normal.