As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IS REPORTING REPETITIVE APU DMM CIRCUIT FAULT, 49-72105. GROUNDED - YES. PERFORMED TROUBLESHOOTING IAW B737-9 IFIM TASK 49-70-00-810-808. NO FAULTS FOUND. REMOVED AND REPLACED DATA MEMORY MODULE PREXCAUTIONARY IN REFERENCE WITH B737-9 AMM 49-72-11.