This is the most common method for the OPPO A37 and its variants (A37f, A37fw, A37t). : Completely turn off your device. Button Sequence : Press and hold the buttons simultaneously. Wait for Fastboot
Download and install the official Android SDK Platform Tools. Extract the ZIP folder to an easily accessible directory on your computer. how to open fastboot mode on oppo a37 verified
"First, unplug the phone from any charger. A cable can confuse it." This is the most common method for the