If you own an OPPO or OnePlus phone and are a curious person who likes to go behind the scenes of your phone operations, or your device is having issues, and you’d like to test the hardware to rule out component failure you can access “Engineer Mode” to run a wide variety of Hardware Diagnostic Tests.
Tests include headphone jack, front and back cameras, battery charging, searching for a Bluetooth device, Gyroscope and many many more.
To access Engineer Mode go to the phone app and type *#808#
I’ve taken screenshots of the results of doing this on the OPPO R9s Plus and OPPO R9s below.
The resulting Engineer Mode menu’s are different with some of the R9s menu choices not being in English. Please don’t select these unless you can read Chinese characters and know what that test does!
Engineer Mode Shortcuts
If you use an alternative Launcher like Nova or Action Launcher you can make shortcuts to specific hardware tests by going to Widgets, Activities, EngineerMode as shown below