I recently had a similar issue with my Tinkerboard. I was still using the legacy 4.4 kernel. To solve it:
1, I booted another SD card with TinkerOS
2. Plugged in the SD with Armbian using a USB SD-card adapter
3. mounted /dev/sda1 the partition with Armbian
4. bind mounted /dev /run /proc and /sys on the Armbian filesystem
5. chrooted into Armbian
6. ran armbian-config
7. first switched to the 5.2 kernel, but that didn't boot either, then did above again, switched to 4.19 and Armbian was booting again!!