While using your computer, you suddenly hear loud clicking or grinding sounds and notice smoke or a burning odour emitting from your hard drive.
Do not attempt to power up your computer !
Physical disk component failure may range from a minor damage to circuitry to a horrible mechanical head crash.When this happens, the disk produces weird grinding sounds or stops spinning totally, in worst case scenario, smoke and a burning odour !
These symptoms reveals physical failure and software recovery at this stage will not be helpful and may do more damage than good.
Data Recovery must be done by hardware fixes.
If hard drives are to be opened up, they have to be done in Class 100 clean room environment.