As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI IN, BOTH SAT 1 & 2 LIGHTS ILLUMINATED AND THE SATCOM DOUBLE CHIME SOUNDED. THE SAT OPTION WAS NOT ON THE ACARS MENU, AND ATTEMPTED TO ANSWER, HEARD NOTHING. THE CHIMES CONTINUED FOR ABOUT 2 MINUTES, THEN STOPPED AND BOTH LIGHTS WENT OUT. ACFT GROUNDED. SATCOM OPS NORMAL IAW AMM 23-15-00. SATCOM PROMPT SHOWS & VERIFIED COMMUNICATION INGOING AND OUTGOING CALLS. NO HISTORY 30 DAYS.