this method is a last resort method and use at your own caution.
You need another drive to backup information with this method.
Also, you will probably have corrupt data even if this method works. In a hard drive there are "needles" that can scratch the drive" also there are circuits. Getting thrown is like thowing a plate...you might be able to eat off whats left, you might not.
NOTE: if real critical information you may want a professional data recovery service as this method will probably be a one shot deal
METHOD AS LAST RESORT: Place hard drive in ziplock bag (removing all air possible), put in freezer over night, try again, if works back up immediately, if doesn't then you are more dead then before.