As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE VERTICAL SPEED WHEEL IS INTERMITTENT ON CONTROL PANEL. DURING CLIMB FROM FL360 TO FL370 THE WHEEL WAS UNRESPONSIVE. AFTER ESTABLISHED IN A CLIMB USING LEVEL CHANGE THE V/S MODE SELECT BUTTON WORKED TO SWITCH THE CLIMB INTO V/S MODE BUT THE WHEEL WOULD NOT CHANGE THE RATE. OPERATED NORMALLY LEAVING CRUISE ALTITUDE FOR FINAL DECENT. GROUNDED - YES. NO FAULTS ON DFCS BITE. ALL MCP TESTS PASS. REFB737-800 FIM 22-11 TASK 801 AND B737-800 AMM 22-00-01.