As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CENTER FUEL TANK QUANTITY BLANK. GROUNDED - YES. PERFORMED B737-800 FIM 28-41 TASK 810 REMOVED AND REPLACED CENTER REFUEL QUANTITY INDICATOR ASSY REF B737-800 AMM TASK 28-41-61-000/400-801 AND FUEL QUANTITY PROCESSOR UNIT REF AMM 28-41-81-000/400-801 OPS TEST PASS WITH CENTER FUEL TANK QUANTITY NO LONGER BLANK.