So the issue first started when I was using the hard drive (it's in a external enclosure) and it failed and turned off, I turned it back on and windows recoginsed it and I went back on it and the same happened. Turned it back on and windows didn't recognise the drive anymore, I changed the PCB with a correct replacement to see if this helped and the same as above happened so no result.
So after doing some research on the drive (WD green WD20EARS) I read that these drives have a bit of a firmware issue on the head and can stop the drive booting up, so I then proceeded to think to buy a donor drive to take the head out. So I have done the head swap (used the correct head tools) and still no luck, the drive spins up and the go back and forth a few times and the the drive spins down and stops.
Under computer management I try to initialize drive in either MBR or GPT, when I try GPT it tells me the drive is not big enough for it and with MBR it tells me unable to initialize. I've tried the head with both pcb's and am begging to run out of ideas on how to get this drive back up and running long enough to get the data transferred to a different hard drive.