As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU NO START / NO ROTATION FAULT LIGHT ILLUMINATED. GROUNDED - YES. REF TSR711069 PERFORMED APU OPERATIONAL TEST REF B737-800 AMM 49-11-00. NO DISCREPANCY WITH START, ELECTRICAL POWER AND APU BLEED AIR. NO CURRENT STATUS FAULTS LOGGED. PRECAUTIONARY, REMOVED/REPLACED APU START CONVERTER UNIT REF AMM 49-41-61, OPS NML REF SAME AMM, AND NO CURRENT STATUS FAULTS. GROUND VERIFICATION TEST GOOD.