If no activity, then yes, indicates a hardware issue.
First step / advice would be to do a backup of all your stuff, then do a factory reset. If still an issue...
Physically you will need a Torx 09 to open the front panel.
First what @sezare56 said. You should be able to find 'Compressed Air'
Then like @MichalHo said, check the connectors for the crossfaer are still seated.
Remember to use test mode in between, thats what it is there for.
Good luck.. "All care, no repsonsibility"