If it is a standard PV, try the following
- If it is a model with key pad, press the left arrow and right arrow keys together, <- & ->
- If it is a model without keypad, press bottom two corners of the screen
If it is a PV+, you should have a put a "Goto config button on any of the screens. I have not tried the other way. What I was told is to plug in a USB keyboard, and press Ctrl+Alt+Del keys during boot.
Regards