Oppo A37 Safe format successfully using EMMC done 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
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Dipendra Pathak