From researching the many issues associated with the 5593's, I think the answer to this is HEAT.  The screen being raised into position will Block the ventilation exhaust ports, trapping heat inside.  I would bet you have also had issues with poor performance, and likely some video issues as well-- screen going black.   The solution seems to be that there is no solution.  This is horrible engineering resulting in a failure of heat management.  From there, a cascade of issues results in a computer that effectively can not be used as intended.  Solution?  Dell needs to do a product recall on these machines, and refund customers or replace with a computer that is not plagued by shoddy engineering design.  
Inspiron 5593  Few keys doesn't work such as b, n, 2, space key. Tried everything uninstalling HID event, uninstalling and reinstalling keyboard drivers, updating drivers etc. but nothing helps. Anyone know the fix? Please help.
Few keys doesn't work such as b, n, 2, space key