What was found
AT FL 300 RECEIVED DISPLAY COOL CAUTION. C/W QRH UNABLE TO CLEAR MSG. FAN SET TO STANDBY, MSG BECAME INTERMITTENT OUT OF APPROX FL 180 AND ALL THE WAY TO THE GROUND. INSPECTED COOLING FANS & DUCTS. OPENED FWD KIDNEY PANEL & INSP DUCTS & FOUND NO DEBRIS. R&R LOW FLOW SENSOR. INSPECTED AVIONICS COOLING DUCTING AND FAN ASSYS. OBSERVED FLT FAN CHECK VLV BINDING TO OPEN POSITION AND DEBRIS IN STANDBY FAN. REMOVED AND REPLACED FLT FAN AND CLEARED DEBRIS FROM STANDBY FAN.