Well I don’t have board prints but, they are both 16 Port I/O controllers. U7 runs the spare I/O ports Con 36 & 37 (ports 13 & 12 respectively.) U5 controls Con 39 (Port 10) fire service, EPNP. Static & Dynamic sensors on Con 14, Teach 1 for front HN riser, Teach 2 for rear riser, FSSR & STBC inputs on Con 35 (never seen used) & spare I/O on Con 32 pins 1 & 2 (Port 14 I/O 1 & 2.)
All they have in common is power, it gets P24 through F_P24 from the power supply and 3.3v but that’s generated on the board. And SPI communication with the micro controller U4, also on the IOC.
I think I’d replace the power supply but curious if any of the spare I/O are used on Con 36 & 37.