What was found
WHEN ATC BUTTON PRESSED, KEY FUNCTION INOP IS DISPLAYED ON FMC. GROUNDED - YES. RESET SYSTEM, OPS TEST NORMAL REF B737-800 AMM 34-61-00.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
WHEN ATC BUTTON PRESSED, KEY FUNCTION INOP IS DISPLAYED ON FMC. GROUNDED - YES. RESET SYSTEM, OPS TEST NORMAL REF B737-800 AMM 34-61-00.