the semaphore preiod has timedout

It essentially means that a device driver can't talk to a device.

Check your connections and the drive.

also check termination of this is a scsi.
i have not seen this error. i would be interested in the model numbers of your hd controller and drive

more ideas:
post your os version
post your non accessible hard drive specs (interface, model number)
update your os to latest sp
remove write protection (if applic) from the non accessible hard drive