Factory reset help

I know i'm missing something in the instructions...

I powered the F265s off

I powered it on holding power (upper let) and back (bottom right)

Instructions said to hold them until i hear a beep.  Then release the power.  But I don't hear a beep and the screen goes dark.

I've done this 6+ times.

What am i doing wrong?

Thanks and sorry to be so slow

Len