Good heads v Bad heads

seagate data recovery

Not strictly an accurate statement, the hard drive heads on the top may look ok to the naked eye but they can be faulty. The bottom ones are gone, the black parts hanging off are actually sliders. If a drive is spun up with the heads like this then its game over shortly after. This usually happens after a drive has been dropped. 

These heads came out this drive


This is what they look like up close