Keep hearing a wierd click sound once a day or so Mac Pro 1,1

[Mrbill317]

I have a Mac Pro 1,1 and every day or at least twice a day I hear a clicking sound.
It is not hard drive style click of death sound. For the life of me I cannot tell where its coming from.
Do you guys think it might be the power supply? Everything works perfectly on the machine but that sound worries me.
Is it very hard to swap out a power supply?

 

[lurkingbf]

I hear it, too, on my machine--especially as it warms up from sleep. I'm in my third year of ownership now without issue. I wouldn't worry about it.

My only suggestion would be to always run with a decent voltage regulating UPS.

 

[wafl iron]

it might be the sound of a harddrive being put to sleep. disable that feature in energy saver if it bothers you

 

[multimania]

Happens here too, glad to see it isn't an isolated issue!

 

[nanofrog]

It's likely a PSU relay.