some keyboard keys stopped working

Dear all,                                                             

These (MJU7NHY6) keys in my laptop dell (Inspiron 11-3000 series) keyboard stopped working this May 13. They wouldn’t function unless pressed so hard.

The onscreen keyboard is working fine. I updated the keyboards driver but it didn’t help. I’m sure that no liquid was spilled over the keyboard. Maintenance shops where seem they can’t help. Some said would give it a try but that there’s a chance it may screw up the whole. Please advise what to do. Enclosed is a snapshot of the keys in questions.

I appreciate your advice.

Best,