As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT RETURNED, UNABLE TO MAINTAIN PRESSURE. CABIN WOULD NOT HOLD MORE THAN 1 DIFFERENTIAL PRESSURE CLIMBING THROUGH 10K FEET, CABIN WAS 8,000 FEET. ACCOMPLISHED PRESSURE CONTROL SYSTEM CHECK, NO DEFECTS FOUND. RAN ENGINES AND DUCT PRESSURE NORMAL. AIRCRAFT PRESSURIZED OKAY. RADIO RACK FLOW CONTROL VALVE OFF SCHEDULE AT RENO. REPLACED RADIO RACK FLOW CONTROL VALVE.