HP Prodesk 600 G2 SFF USB ports not reacting to device insertion

I'm reimaging an HP ProDesk 600 G2 SFF for work, and everything works except the USB 3 ports on the back, and all of the front-facing USB ports. The only ports that consistently work are the USB 2.0 ports that HP indicates are meant for keyboard/mouse. I've tried the following, to no avail:

• Reinstalling Windows 7 from the factory supplied reinstall media (not from our organizations Win 7 image) and reinstalling the drivers.
• Checking the power supply and motherboard for discoected or damaged cables.

This is an image of the relevant section of the motherboard.

APPENDIX: SPECS * Intel Core i7 6700 @ 3.4 GHz * 32 GB DDR 4 RAM * 1 TB HDD * Chipset resident graphics (Intel HD)