Gestetne Dsm520pfr

first: our fax was its LCD (open heat error) then we replaced :
1- power supply board
2-fusing unit
note: fusing was in a good case
and fax work well for one day
second the same fax its LCD display (scanner locked) we replaced scanner unit and LCD display (open heat error) again we replaced power supply again and fax worked well but after that lcd display (open heat error)
as you see we replaced power supply board for 2 times
is there any way in tech mode to reset message (open heat error)
note : in all cases fusing unit is in a good case