Evaluate the plant!  Are there any insects (usually scale on the underside)?  If not, is it a disease?  Normally, a disease would affect all parts of the foliage not just the older fronds.  It could be a nutritional deficiency probably lack of potassium.  This can affect palms and cycads both.  Purchasing a complete palm special fertilizer that contains a slow release of nitrogen and potassium, plus extra magnesium and trace elements is recommended when buying a blended palm fertilizer.