Look here
http://docs.info.apple.com/article.html?artnum=58418
The PCI Graphics (Yikes!) and AGP Graphics (Sawtooth) have the power pass through exposed. This is because the pass through is used to power a monitor. The Gig Ethernet and Digital Audio don't need the pass through because they are designed to use ADC monitors which draw their power through the ADC port on the video card. The pass through is still there, though, the plastic cover that goes with these machines just covers it up. My Digital Audio has one covered up like is shown on the Apple page. If your DA or GE does not have it covered, then someone swapped the plastic cover with one from an earlier model. There should be a white label with a bar code and the description of the machine on that cover. Check it to see if the description on the label matches the machine it is attached to.
http://docs.info.apple.com/article.html?artnum=58418
The PCI Graphics (Yikes!) and AGP Graphics (Sawtooth) have the power pass through exposed. This is because the pass through is used to power a monitor. The Gig Ethernet and Digital Audio don't need the pass through because they are designed to use ADC monitors which draw their power through the ADC port on the video card. The pass through is still there, though, the plastic cover that goes with these machines just covers it up. My Digital Audio has one covered up like is shown on the Apple page. If your DA or GE does not have it covered, then someone swapped the plastic cover with one from an earlier model. There should be a white label with a bar code and the description of the machine on that cover. Check it to see if the description on the label matches the machine it is attached to.