Oppo A37 Safe format successfully done using EMMC by Hydra Tool
1. Run Qualcomm Tool of Hydra.
2. Choose Module and Brand
3. Choose "Service"-->"Universal" Tab.
4. Choose "Ultra Power" from drop down menu.
5. Choose "Safe format".
6. Click on "Execute"
7. Connect device to the computer with USB Data Cable.
8. Wait until the operation is complete
Screen Short:
Mount Everest