I have a Dell Inspiron that doesn't seem to get past the initial POST - it turns on and displays the logo, and the loading bar fills about 60%, but can't boot into the OS, enter Setup (F2), or display the alternate boot options (F12). I tried swapping the RAM, in case that was faulty, but it didn't help. What now?
I called Dell, and they suggested that the issue might be that the hard drive was defective, and that the hard drive was being accessed as part of the boot sequence. My guess is that this is because the BIOS examines if the hard drive has specific data on it, that is needed to provide Dell-specific functionality.
In short, removing and replacing the hard drive was sufficient to fix this problem. I hope that this information is useful for whoever else encounters this issue; it was a learning experience for me.