Casio wk1630 Repair question

There's a group of 8 white keys and 5 black keys that play once, sustain and then no longer play at all until the keyboard is turned off and the problem repeats. Is this a problem you're familiar with and can fix?

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

crwdns2934109:0crwdne2934109:0

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