As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OXYGEN LO PRESS IMMEDIATLEY AFTER TAKE OFF OXY PREE GAUGE READS 0 PSI-C/A-FOUND 02 GAUGE TO BE READING 1650 PSI. COCKPIT INDICATION READS ZERO DEFERRED OXYGEN PRESSURE INDICATION SYSTEM MEL 35-01 AUTH 020878-B. REMOVED AND REPLACED O2 CTRL TRANSFERRELAY K0417 NO DEFECTS NOTED CB'SOK O2 INDICATIONJ NOW READING OK MEL ITEM RESTORED.