model num:tm-f3/5


hi guys
hope you can help me i bought the box 3 months ago i allways had touble with the edge of the picture on my favourite show so i went on to video format button and change the 1080i to 1080p to be honest i am not sure if it was the other way around but as soon as ichange it the screen went blank with "invalid scan freq"
the box is still working but its impossibe to access to return it to factory condition
please can you advise