Location of the SMC Reset button in a Mac Pro

I'm having trouble finding the SMC reset button.

+The hatter+ said, "use the SMC RESET button inside, under drive #4. "

This page http://docs.info.apple.com/article.html?artnum=304123 said;

"Another way to reset the SMC on a Mac Pro computer is:

From the Apple menu, choose Shut Down (or if the computer is not responding, hold the power button until it turns off).
Open and remove the metallic outer door.
Press the SMC_RST switch that is located slightly below and to the right of the row of diagnostic LEDs. Use a non-metallic, non-conductive object, such as a wooden pencil.
Replace the metallic outer door.
Press the power button to start up your computer."

I can't see any row of LED's - can't even see one inside there...

Can anyone help me with the location of this button?

Thanks