This is SUPER disconcerting to me. Is it a standard thing?

@larrydavis: Could just be the plastic expanding from the heat. I know my PS3 slim makes popping sounds all the time on startup and after I turn it off due to the heat making it contract and expand

My TV does that, but this is one pop when I hit the power. I think it's the fan, but I'm not sure if that's a regular occurrence.

What did I tell you about putting pop rocks in the disc tray?

Gosh dang it dude I can't help it! I have tons of them, I have to put them somewhere! Is it a problem that I also poured coke in there?

Yep, I clicked because I read "pooping noise." I'm very disappointed.

Same with my PS3 Slim.

I honestly don't notice it most times because I'm getting situated before I sit down. It happens.

I hear it. I'd just call it a click. It's pretty clearly how the unit is turning power on and off to the high powered parts of the unit. I don't think it's the fan.

It doesn't bother me.

My PS3 fat makes the same sounds when I turn it on and off and I've had it for five years with no issues. I really think it's just the unit powering on and off like flippy said.

The click sounds like a circuit being completed to power the unit on, I heard it too.

(But then mine died. That may not bode well for you.)

I really read that as pooping noise. I'm disappointed to say the least.

Its the PSU mechanical relay. Absolutely nothing to worry about. My Mac Pro's relay like a shotgun blast (not really.)