You may have a dead lithium battery . When that happens it will lose all of the sounds and it could make the display do funny things as well . When was the last time the lithium battery was replaced ( they last about 6 years ) . The cz-1000 came out in around 1985 so it is old . All this is asuming that it has not been dropped or something . Once you replace the battery , you will need to reload the sounds from a factory sound cassett or from someone who has stored patches on cassett .