Click sound when waking Mac

[Silly John Fatty]

When I wake my Mac Pro it makes a click sound, is this normal?
It's the Mac in my signature. I've always wondered if this may not be something wrong, I've bought it refurbished from a seller a few weeks ago.

 

[Ironjer]

It is absolutely normal. The sound come from Relay

 

[flowrider]

Probably the sound of the HDD waking up. In my experience WD drives are noisier than other drives and make clicking sounds. It OK, nothing to worry about.

Lou

 

[Silly John Fatty]

Well its a seagate barracuda. What relay?

 

[DanielCoffey]

It is most likely to be the relay inside the power supply - it clicks when you turn the machine on or off and is normal.

 

[Ironjer]

Relay is located in power supply

 

[NOTNlCE]

+1 on the PSU relay. Happens in both my Mac Pros and in my old G5.