Product: PE6R4, PE6R4-I
Computer: MacPro or Mac PPC
Operating System: 10.5 or 10.4
Application: Protools Digidesign & other 3.3v PCI cards
MacPro not booting up when Magma Expansion Chassis is attached, and it has PCI cards installed in the Expansion.
When there are no cards inside the expansion system, I have no problems booting my MAC.
This problem could be attributed to a 5vload resistor not connected or a defective expansion board and host interface card.
First thing to check is the 5vload resistor:
1. Check the 5vload resistor (gold metal in color) make sure that is connected to the internal power supply. if it is not connected reconnect it to the white housing connector of power supply
Also, check the two wires(black and red) make sure this is coming out from the plastic housing connector.
2. Swap the Expansion board and Host Interface card
This is a picture of a 5vload resistor: