As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A/P MODE CONTROL PANEL "IAS/MACH" WINDOW HAS DAMAGED LCD JUST TO THE LEFT OF ALL DISPLAY DIGITS THAT IS CONSTANTLY LIT MAKING AIRSPEED READ AS A NEGATIVE NUMBER. GROUNDED - YES. REMOVED & REPLACED DFCS MODE CONTROL PANEL. ALL TESTS PASS. REF B737-900 AMM 22-11-34.