Having designed these screens before, often times the password is something mindless like zeros. If you luck out and it's a pin rather than unbounded input, try

Having designed these screens before, often times the password is something mindless like zeros. If you luck out and it's a pin rather than unbounded input, try zeros or sequential numbers. Usually a well meaning engineer adds the functionality and rigorously tests it... then customers not wanting every technician to ask the local store for a password have every unit set to the same exact easy to guess password. Or so I hear.