Kurzweil MIDIboard 5 volt issues

Hi, folks:
I’ve got a Kurzweil MIDIboard that is giving me an error 14 (13) error. I measured pin 16 on U26, and it’s giving a 6.18v reading which I know is too high. I also noticed on pin 7 is giving a -6.04v reading. Is there are trim pot I’m not seeing that adjusts this? Where do I correct this issue?