You can, although you do need to make a small change to the power supply to do so.
AGP Graphics Logic Board Power Connector
Gigabit Ethernet Logic Board Power Connector
The big difference is in the positioning of the trickle (TRKL) pin. On the AGP Graphics pinout, this pin is a +5v rail, second from the top on the left. On the Gigabit Ethernet pinout, another row of pins has been added to the top, and this pin is the +28v rail on the right. All you need to do is move the 5v wire from its current position on the Sawtooth PSU and connect it to the Gigabit Ethernet logic board where the 28v wire would normally go. Even though it's supplying a significantly lower voltage, it's still enough to start and run the machine, but ADC displays will not work, along with some higher voltage FireWire devices that draw power directly from the system.
The other wire that differs is the third pin down on the right. On the AGP Graphics pinout, this is a "POK" (Power OK) line. On the Gigabit Ethernet, this is a 3.3v line. I haven't modified this wire on mine and the computer still seems to work fine.
Of course, you could also just get a Gigabit Ethernet power supply to match and skip all the hassle completely.
Apart from the small power supply differences, the boards are otherwise interchangeable between models.
AGP Graphics Logic Board Power Connector
Gigabit Ethernet Logic Board Power Connector
The big difference is in the positioning of the trickle (TRKL) pin. On the AGP Graphics pinout, this pin is a +5v rail, second from the top on the left. On the Gigabit Ethernet pinout, another row of pins has been added to the top, and this pin is the +28v rail on the right. All you need to do is move the 5v wire from its current position on the Sawtooth PSU and connect it to the Gigabit Ethernet logic board where the 28v wire would normally go. Even though it's supplying a significantly lower voltage, it's still enough to start and run the machine, but ADC displays will not work, along with some higher voltage FireWire devices that draw power directly from the system.
The other wire that differs is the third pin down on the right. On the AGP Graphics pinout, this is a "POK" (Power OK) line. On the Gigabit Ethernet, this is a 3.3v line. I haven't modified this wire on mine and the computer still seems to work fine.
Of course, you could also just get a Gigabit Ethernet power supply to match and skip all the hassle completely.
Apart from the small power supply differences, the boards are otherwise interchangeable between models.