As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF PASSING THROUGH APPROX 25000 FT CABIN RATE INCREASED DRAMATICALLY & CABIN WAS NOT PRESSURIZING, AUTO CONTROLLER WAS NOT RESPONSIVE & DISPLAY SHOWED 48102 IN WINDOW. UNABLE TO CHANGE LANDING ELEVATION. SEE LOG PAGE 3796251 FOR MORE INFO. DEFERRED THE PRESSURIZATION CONTROL SYS, AUTOMATIC & MANUAL MODE IAW MEL 21-18. MX PROCEDURE COMPLIED WITH. R & R ELECTRO PNEUMATIC OUTFLOW VLV IAW AMM 21-31-03. OPERATIONS CHECKED SATISFACTORY. THIS RESTORED MEL 21-18.