Clean with alcohol ONLY!! Do NOT use the cleaning solvent or you just cost yourself $225 dollars or so. Gently wipe both sides with a soaked soft cloth...gently do this several times. You may try using a flashlight to shine directly onto the scale to see if you have ink or major scratches. After your cloth is clean after several wipes, so a Environmental Match (on your menu - ENV Match). If this fails you have a bad scale and must replace it. Even your fingerprints (oil) can make the scale seem bad, so be very careful handling it. This should help. Good luck.