As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLIMBING THROUGH 13,000 FEET CABIN SPIKED TO 10000 FT. FOLLOWED QUICK REFERENCE HANDBOOK AND WAS ABLE TO REGAIN CONTROL WITH MANUAL CONTROLLER. RETURNED TO SLC. REMOVED AND REPLACED ELECTRO PNEUMATIC OUTFLOW VALVE PER MM 21-30-04. RAN AIRCRAFT PRESSURIZATION SYSTEM PER 21-30-00. OPS CHECKS GOOD.