When you say, 'working forever' do you mean it's continually spinning? If you're noticing it start to spin and doesn't stop AT ALL and you can't access or get a drive letter then chances are the logic board (the circuit board on the bottom of the drive) is broken/faulty OR the adapter on the sata power and data ports is bad and needs to be replaced, that one is easier to replace than a logic board but you'll still need to contact the manufacturer or brand to see what your options are. Perhaps you could also scour ebay to find the replacement part.