Altech UEC DT 3900 - Manual (Page 21)

21
FACTORY DEFAULT
The DT3900 allows you reset to factory defaults via the setting section in
the menu.
It is important that you do not perform this function unless absolutely
Necessary.
Perform this function if you have moved to another location and need to
rescan the set top or the set top is performing erratically and may need
factory settings to rectify the problem.