Buttons on 48GX don't work

Buttons 0, 1, 4 and 7 don't work anymore. I reset and replaced batteries and it still doesn't work. Any idea?

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0