As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TECH SERVICE REQUEST. CHECK FQIS SYSTEM IN THE LEFT TANK TO PREVENT POTENTIAL INCORRECT FUEL QTY READINGS. GROUNDED - YES. PERFORMED TANK AND COMPENSATOR UNITS TEST REF B737-800 AMM 28-41-21-710-801. FOUND COMPENSATOR PROBE F15L, TANK PROBES F6L AND F10L OUT OF CAPACITANCE LIMITS. REMOVED/REPLACED F15L, F6L, AND F10L REF AMM 28-41-21/401. OPS/LEAK CHECK GOOD.