As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORT: DURING ENGINE 2 START USING APU PNEU DUCT PRESSURE DROPPED BELOW 10PS AND WOULD NOT START. CREW TRIED A CROSSBLEED START WITH THE SAME RESULT DUCT PRESS DROPPED BELOW 10 PSI DURING START ATTEMPT. REPLACED STARTER PER MM, OPS CHECKED GOOD.