Long before a phone arrives in your hands, it goes (or should go) through a wide range of hardware diagnostic tests designed to check for any potential faults before it is packaged and shipped out.

As Mishaal mentioned in a previous article looking at accessing these tests on Huawei devices, if you are buying a used device then taking the time to run a few of theses tests can save you a trip back to the store/seller in the event that there is a non-immediately obvious hardware fault. When running Oxygen OS, you can access these tests by typing "*#808#" into the dialer app -- this will open a page with a complete list of the diagnostic tests available, including root checking and an option to erase all data on the phone. Typing "*#80X#" will take you straight to individual tests based on the number you replaced X with.

Launchers such as Action Launcher 3 and Nova also offer the ability to add a shortcut to these tests and menus to your homescreen via the Activities Launcher, simply head to Widgets, Activities, and then scroll down to EngineerMode.

There are a huge number of diagnostic tests available, so if you ever suspect that a hardware fault may be to blame for an issue instead of a software problem, you may be able to identify the cause through these menus which include (but are not limited to) tests for:

  • Screen components
  • Hardware keys
  • Speaker impedance
  • Vibration
  • Headset plug
  • Charger (normal & fast)
  • LCD brightness and effects
  • Gyroscope
  • Msensor
  • Proximity Sensor
  • GPS
  • etc

This code isn't just limited to the OnePlus 3 & 3T, and will work on most OPPO devices as well. If you are not running a OnePlus or OPPO device then don't worry, it is very likely that your device has an equivalent app hidden away. Be sure to also check out our guide for Huawei phones and if you know how to access the hardware diagnostics for your device consider leaving a comment below for others!


Thanks to Viren for suggesting this story!