Info about Samsung Galaxy A71 - a71
Boot Modes
Recovery
With the device powered off - hold Volume Up + Power while the device is connected to a PC via USB cable.
Download
With the device powered off - hold Volume Down + Volume Up and connect the USB cable to PC.
[ROM][15][a70q][OFFICIAL] crDroid 11.14 Samsung Galaxy A70 | XDA Forums
You need to unlock your bootloader by enabling OEM unlocking on developer settings,
Then we must enter download mode by holding volume up and down and then plug in a usb cable connected to your computer. You should see a green screen with instructions to unlock the bootloader, by following them your data will get wiped and the device will boot to setup, set it up so that it has network connection, no need to add acounts or anything. Check that OEM unlocking is now enabled and gray.
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(on dirait que c’est ta première install de /e/, et que tu ne lis pas les liens que l’on te donne…)
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(7) Flash a custom recovery manager on your device
heimdall flash --VBMETA vbmeta.img --RECOVERY recovery.img --no-reboot