As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PERFORMED AN AIR TURNBACK DUE TO AN AUTO INOP LIGHT ON PRESSURIZATION PANEL, WHILE CLIMBING THROUGH 10K. CABIN ALTITUDE ALSO NEAR 10K AND CLIMBING. SWITCHED TO MANUAL ON CONTROL WHEEL, BUT WHEEL WOULD NOT ROLL. WE WERE UNABLE TO REGAIN CONTROL OF CABIN ALTITUDE. REPLACED THE OUTFLOW VALVE ACTUATOR ASSY. OPS CHECK OF OUTFLOW VALVE ACTUATOR ASSEMBLY GOOD.