Apple imac 17in 1ghz Servicehandbuch
iMac (17-inch Flat Panel, 1GHz) Take Apart -
Lift the power supply and metal shield out of the chassis (Faraday cage).
When replacing the metal shield (see picture above) that sits on
top of the power supply, install the two shorter screws near the optical door. If the
longer screws are installed by mistake, the screws will scratch the inside of the
housing (circled below).