My car wont change to 5th ger

Front wheel drive type AE 90 series
common problem
possibles
is this a cables shift ..see if the cables can be adjusted at the box
take the cables off the box and check the stick has full movement
to the fifth gear position
check the engine mounts
if the clutch was recently changed I would suspect that

box has to come out for the next repair /inspection
the syncro of the fifth gear is damaged
the rolled steel pins at the internal selectors has bent or broken
option
try to source another good second hand box and fit that