A test mode is a mode, usually hidden, inserted into consumer electronics by the manufacturers. They are generally only intended to be used by authorized maintenance people. Others sometimes discover them however, not always intentionally. Test modes usually include functions such as displaying test card images and testing moving parts, things that are generally useless to a general consumer who does not know anything about how the device works.
Test modes are also inserted into consumer handhelds and are often found as a hidden access mode in electronic games. Its main focus is to test the functions and sound files to confirm that all the sounds are present and the sepaker is working. The sound files are stored on a chip on the circuit board. Some electronic games do not play every sound in their test mode. To access the test mode on an electronic handheld game, it involves pressing a combination of buttons and inserting a battery or holding the reset button. Some sound playback test modes can be automatic like the Bop It Shout and the Bop It XT and some test modes are manual like Bop It Beats which means that one button on the electronic device will play a sound, repeat a sound or go back one sound. Some test modes might be a menu where each function of the device will do something different to the other button. Some indications that the electronic device is in test mode is that the device might beep, play a sound or say a number. Some test modes may even have a hidden melody such as Tiger Electronics' Brain Shift game which plays Happy Birthday. Manufacturers like Hasbro do not share test modes publicly online. They are usually found by electronic game owners and enthusiasts and videos on how to get access to them are shared online.