As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NO SATCOM PROMPT ON FMC AND NR 1 SAT BUTTON ILLUMINATED BLUE. ACFT GROUNDED. PERFORMED OPS CHECK OF SATCOM SYS REF AMM 23-13-00-730-801 AND NO DEFECTS NOTED. TRANSFERRED POWER FROM GROUND POWER TO APU POWER SAT COMPUTER RESTARTS AFTER 40-50 SECONDS AND SAT PROMPT RETURNS. SATCOM RE BOOTS NORMALLY AFTER POWER INTERRUPTION.