As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON POWER UP LEFT FMC FAIL LIGHT. GROUNDED - YES. FOUND LEFT MCDU SCREEN BLANK ALONG WITH FAIL LIGHT. PERFORMED FIM 34-61 TASK 804 (CYCLED BOTH MCDU CB'S) AND NORMAL CDU PROMPTS DISPLAY, FAULT LIGHT EXTINGUISHED. REPAIR CONFIRMATION PASS. FMC'S CDU INSTALLATION TEST GOOD REF AMM 34-61-01. CLEARS MEL 34-36L.