What was found
CABIN ALT WARNING MSG DURING CLIMB OUT. AFTER TAKE OFF DURING AFTER TAKE OFF CHECKLIST, APU BLEEDS DID NOT SWAP NORMALLY AND PLANE DID NOT PRESSURIZE AT ALL. RAN QRH AND DESCENDED TO LOWEST ALTITUDE ALLOWED BY TERRAIN. ON DESCENT BLEEDS SWITCHED OVER AND AIRCRAFT BEGAN TO PRESSURIZE AGAIN. DIVERTED TO GJT. NORMAL LANDING AFTER THAT. (FLIGHT 3043 FILED CLOSED)RESEARCHED LINEVEIW BACK 30 DAYS. NO HISTORY OF ANY PRESSURIZATION ISSUES. INTERROGATED MDC HISTORY NO STORED B1 CODES FOR PRESSURIZATION ISSUES. PRESSURIZED A/C IN REFERENCE TO AMM 21 -31-00-910-801 A/C PRESSURIZATION NORMAL. REMOVED AND REPLACE CABIN PRESSURE CONTROL PANEL IAW AMM 21-33-01 PREFORMED OPS CHECK OF CABIN PRESSURE CONTROL PANEL IN REFERENCE TO 21-33-01-710-801. OPS CHECK GOOD.