As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LT FMC FAIL W/VTRK ON LT NAV DISPLAY AT CRUISE. TRIED (USING FMC FAIL C/L) TO RESTORE BY PLACING FMC SOURCE SEL SW TO BOTH ON RT. TEMPORARILY RESTORED BUT AFTER SWITCHING TO NML, HAD IMMEDIATE LT FMC FAIL AGAIN. CONTINUED ON SINGLE R FMC. GROUNDED - YES. RE-BOOTED LT FMC - SYS OPS OK. NO HISTORY.