EN-21 FD SeriesTABLE 4-1. TROUBLESHOOTING.4 MAINTENANCE4.1 CalibrationVerify calibration periodically by placing either a ASTM Class 4 weight or an OIML Class F2 weighton the scale and compare the reading to the specifications. Refer to Section 3.7.1 for calibrationprocedure.4.2 Cleaning• Disconnect the scale from the power supply before cleaning.• The housing and pan should be kept clean and free from foreign material.• Wipe the exterior components of the scale using a soft cloth dampened with water and a milddetergent (do not use acids, alkalis or strong solvents).• The leveling feet and load pads may be unscrewed and removed for cleaning.• Do not allow liquids to enter the scale.• Remove and clean the pan separately from the scale.• The pan is dishwasher safe and may be placed with normal loads. All other parts must not beplaced in a dishwasher.4.3 TroubleshootingThe following table lists common problems, possible causes and remedies. If the problem persists,contact Ohaus or your authorized Ohaus dealer.Cannot calibrate the scale. Calibration locked. Set LFT to OFF in the Menu Mode.Set LCAL to OFF in the Menu Mode.Set Security switch to the Off position.Weight reading does notstabilize.SymptomConnect scale to power.Connect scale to power and charge battery.Scale will not turn on. AC power not connected.Battery discharged.Battery indicator is low. Battery discharged. Connect scale to power and charge battery.Possible Causes RemedyUnstable environment.Interference under pan.Ensure a stable environment.Ensure that the weighing pan is unobstructedand free to move.Change the Averaging Level setting.Scale does not displayaccurately.Improper calibration. Calibrate scale.Battery fails to charge fully. Battery is defective. Have the battery replaced by an authorizedOhaus service dealer.