20" iMac G5 2GHz (No SMU/PMU button on the motherboard as shown on Apple's site..)

How do I reset the SMU/PMU on my 20" iMac G5 2GHz? (There is no button on the motherboard as shown on Apple's site..) Thanks..

PS. Machine doesn't boot. I heave removed the back cover and tested the power button. LED1 lights up and the instructions on apple's site say to try the SMU reset button next. There are two sets of little terminals for similar buttons and two little symbols the same size as the power button symbol printed on the board but no actual buttons. Any help welcome, thanks.