As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MCP IAS/MACH KNOB WILL NOT CHANGE AIRSPEED NUMBER. IT IS FROZEN. GROUNDED - YES. RESET MCP C/B'S REF AMM 22-11-34, IAS WINDOW OPERATED NORMALLY & THEN FAILED AGAIN AFTER MCP TEST. REMOVED & REPLACED MODE CONTROL PANEL PER AMM 22-11-34, INSTALL TEST PASSED. REMOVED UNIT IS S/N 31019090.