NanoPi K2 problem at startup

[MOEX]

My NanoPiK2 is installed with Armbian Focal desktop system.
When I used it normally for a day, I manually shut it down (closed properly). But when I restarted it, it finally displayed and stayed at

 [OK] Reached target Host and Network Name Lookups.

Unable to enter the system.

I tried to insert the SD card into the computer to search for the boot logs, but I couldn’t find it.

How do i solve this problem？THANKS