Hidden Menu on HP Printers

How I Found It

A while ago, I was doing something on my HP ENVY Photo 7858 printer. At the home screen, I accidentally pressed the Back button another time. I found this:

I entered the menu, and saw this:

What I Did

I looked through the settings, and it eventually became clear that this wasn’t supposed to be accessed by normal users. Instead, it was for technicians who needed to do more advanced things than the normal interface allowed. There were settings for resetting things, running diagnostics and even “setting boot mode to user mode”, whatever that is. I didn’t actually change anything, out of fear of breaking something.