Problem locking and unlocking with key

Hello all my name is: john My central locking has stopped working on my mitsubishi gto 1990-1991 locks from inside but not with the key any ideas thanks

Not sure I can help. Is it both sides: driver and passenger locks? Do the auto windows open and close work?

Its was the passenger door first now its both doors the tailgate opens with the key thanks for the reply

Joe has a video on how to tear apart and refurb your lock cylinders.

Can you send me the video please

Hi there, it will be one of these, Can’t remember which one specifically, but all relate to Locks,