My equal(=), Ans and dot (.) button doesn't work. They show 0.

Some buttons on my calculator don't work. These are Ans, dot(.) and the equal (=) buttons. They all display zeros(0) when I press them. I can't even solve anything because the equal button doesn't work. It only shows zero. It's a Casio fx-991 es plus calculator.

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

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0

crwdns2942205:01crwdne2942205:0:

If you cannot get help here to clean the keys yourself, do not send it in to CASIO to be repaired, its better to buy a new one and sell this one for spare parts on EBay. The cost of shipping will be more than the price of a new calculator.

crwdns2934271:0crwdnd2934271:0crwdne2934271:0

crwdns2934285:0crwdne2934285:0