Which of the following is an unnecessary troubleshooting step when a multi-touch screen is responding erratically?

Adjusting screen brightness settings is considered an unnecessary troubleshooting step when dealing with erratic responses from a multi-touch screen because screen brightness primarily affects visibility rather than touch sensitivity or responsiveness. Issues with multi-touch functionality are typically related to hardware, software, or calibration problems.

For example, resetting the device in a general reset can help clear temporary glitches that may be affecting touch performance. Performing a factory reset returns the device to its original settings, which can resolve persistent software issues causing touch problems. Resetting the home screen layout can also be beneficial as it might fix UI-related issues that could influence how touch inputs are processed.

Therefore, while brightness settings can be adjusted for better visibility, they do not directly address the responsiveness of the touch screen itself and, as such, are not a relevant troubleshooting step in this context.