This happend to me on J3 2017, I left it for more than 48 hours but nothing. Then phone batery ran out, so phone reseted and firmware was deleted. I needed to download new firmware with Odin to phone from https://www.sammobile.com/firmwares/. It took me 8 hours too download it, becaose that site has Premium with normal download speed, but you need to pay ...
Answer is too late, but may be helpful for future visitors.
when I have data on my phone and factory-reset the phone, the data is unrecoverable, since a new key for the encryption is being created and the old one is getting deleted. Am I correct?
You are right.
what happens when I delete data on my phone and then reset the phone - can the deleted data ...
HOW DELETED DATA IS RECOVERED?
Data (un)deletion strongly depends on how a storage media (HDD, SSD, eMMC etc.), filesystem (NTFS, FAT32, ext4 etc.) and OS save and delete files.
File carving / signature search / content-aware recovery identifies standard signatures values in the headers of deleted files (as file command and antivirus programs do to ...
When the device is encrypted, the decryption key is only known by the current OS.
If you know the pin (for that screen you get before the animation starts), the device can be decrypted and get booted up successfully.
If you don't remember that, then you will need to reset the device. This resetting is similar to a factory reset.
Factory reset will not ...
Since you have nothing left on your device, you can try re-flashing the stock ROM by downloading the flash file and flashing it via Odin. It should reinstall the corrupted modem drivers and system files.
Some phone needs to be plugged to light before it can boot to recovery mode/hard reset. Try putting the plugged charger in the phone when it's switched off and immediately it shows the charging signal press the volume down⬇key+power key, if that doesn't work try volume up⬆key+power key.
The both work for my phone innjoo i2s.
Posting this as answer in case anyone else runs into this.
It turns out that I had manually disconnected my Google account years ago, when I switched to a new phone. By reconnecting the Google account, it added the Privacy section (including the Factory Reset option) back into the Settings app. Once that option became available again, the reset worked with ...