Have you used a circuit tester to probe not just the (?) 20amp fuse to be sure both sides show power, but also the 12v outlets etc? There are special USB power outlet meters as well.....
But if the PO was gadget mad, I sure hope he didn't damage the USB outlet itself.
www.harborfreight.com
But if the PO was gadget mad, I sure hope he didn't damage the USB outlet itself.

6/12V Circuit Tester with 5 ft. Lead
Amazing deals on this 6/12V Circuit Tester With 5Ft Lead at Harbor Freight. Quality tools & low prices.

Klein Tools Type-A USB Digital Multimeter ET900 - The Home Depot
The Klein Tools ET900 is a USB digital meter for common standard USB-A (Type A) ports including Qualcomm Quick Charge ports. It accurately and reliably measures and displays the USB port voltage, current,
www.homedepot.com