WD6400AAKS - help! S.O.S.!

I’ve got a WD6400AAKS that has been at the center of a lot of work done with my computer as a “store to” drive. Recently it’s died on start-up, there is no rotation and I can hear a very faint tick, actually it’s like tick-tick-tick few then in 1 or 2 seconds it does it again and that’s it. I had been using it externally for about 6 months. I have tried to re-install back into the desktop but the symptoms remain the same. I’d like some explanation as to what may be going on with it. I have recently purchased a used and working WD6400AAKS drive in the hopes I may be able to swap the PCB board to cure my drive and at least long enough to rescue my data. Both Caviar Blue drives were built 1 year apart and the PCB boards have slightly different part numbers on them. Is there any possibility I can reviver this HDD?