Hello guys hope you can help an amateur

I have the above named external 2.5" drive that is 320GB. It sometimes makes a noise, a bit like two tones of beep, not clicking. When it has detected it comes up as 2TB so I cant get the data off it. The drive is under warranty and Western Digital are sending me a replacement and require that I send the faulty one back to them after 30 days (which I thought was pretty good of them).
The PCB is a strange looking one with a built in mini usb connector, no sata etc.
Would swopping the PCB out from the replacement drive give me any chances of getting the data back?
Or is that a no go?
I have a pretty well stocked workshop with Universal programmers and Tsop/sm component removal is no problem at all. It's just data recovery on drives that is all new to me!
Any advice at all would be really really appreciated.
Thanks Ritch50