Questions:
How to install the new 500 or 550 Watt Power Supplies on the expansion board?
My Old power supply has two 20pin ATX power cables, but the new 500 and 550 have only one 20pin ATX power cable, which ATX slot on the expansion backplane should I install the new power supply?
Answer to Question#1
The expansion backplane has a slot for the 20 pin connector. The new 500 and 550 power supplies have 24pin ATX power connector, which works OK with the 20pin slot of the expansion backplane
The male ATX connector on the power supply has a wide locking tab; make sure this tab aligns with the tab on the female ATX connector. Note that the break away 4pin portion of the ATX connector sits on the right side when the connectors are mated.
Coming from the power supply power cable, There is an extra ATX12V 4-pin connection, snap off the 4-pin cable or leave it as is. Connect the remaining 20-pin ATX power cable to the 20pin slot of the expansion backplane as shown from the picture below
Answer to Question#2
Install the 24pin ATX power cable on the primary ATX slot of the expansion backplane.
The Following expansion boards have two 20pin ATX slots, you should only use the primary ATX slot.
PE6R4-I....................use the primary ATX slot labeled as J12
ExpressBox7..............use the primary ATX slot labeled as J41
7slot PCI 64bit...........use the primary ATX slot labeled as J3
13slot PCI.................use the primary ATX slot labeled as J1
Eb7..........................use the primary ATX slot labeled as J44