is it normal?

[zoran]

to hear my TM disk working, but TM not performing any backup action?

 

[miles01110]

Yes, it is normal for electronics with moving parts to make noise.

 

[PinkyMacGodess]

I don't believe that the drive in the Time Machine spins down the way that my Seagate external does. I would imagine that if it supports SMART or some other technology that it needs to check itself occasionally...

 

[Gregg2]

The point has been missed. TM is not working*. I don't use it, but just trying to help out. A better thread title would help too. And more info about * that ^