Dell PowerEdge 2900 Backplane Power Pinout

Could someone with a working 2900 do me a favour and grab a multimeter and get some voltage readings from the PDB or the Backplane? Specifically I need the voltages for the BKPLN connector (top left in this image):

 

The grey wires could be ‘power good’ if Dell have used the standard colours for Molex connectors.

If they are, they should go from 0V to 5V when the power supply voltage has stabilised shortly after powering on.

I would be very grateful if anyone can confirm this as I am planning to use a 2900 backplane to build a drive enclosure for a mini itx file server.

Source:http://en.community.dell.com/support-forums/servers/f/956/p/19464446/20184257.aspx

It’s mostly the grey wires I’m curious about, as I’m guessing the black is GND and the yellows are +12V; I’m trying to work out whether the +5V supply to the SATA drives is fed directly by the PSU or stepped down on the backplane board. Also, if the grey wires AREN’T +5V, then what on earth are they?