I have a T620 (not GPU ready, but I'm OK with lack of built-in supports).  Will have 1100W PS and 6 fans.

The power distribution board looks like the image below.  3692K cable for the T620 I've seen has the right connectors on the PCI-E side, but not the right connector to finish on the PS board side.   It seems like some cable between the PS board and the 3692K is needed.  (See my reply to this for likely answer...)