Micro SD card is erased and changed to one config.txt

I am using Rock4C+.
I used to use it normally, but (perhaps I made a mistake in the setting of rsetup…) suddenly it stopped working.
Even if I burn the OS to a micro SD card, after turning on the power, the blue lamp blinks, but the boot screen does not appear on the monitor.
Instead, the micro SD card has been wiped from everything from the OS, and instead only one file “config.txt” remains.
This file has the following description:

rsetup config file

Configurations here will be applied on every boot.

Additionally you can create before.txt and after.txt in this folder.

They will run before and after this file, and will be deleted in the end.

This makes them suitable for one-time setup.

Please let me know if you know what kind of setting should be done for normal use as before.

This is normal and expected. On our latest system we have an additional config partition to store some custom config files, and what you saw is the expected result after the first boot configuration has been completed.

Please follow this instruction and see if you can access the serial console.

Thank you for your answer.
Try immediately!

I tried as instructed, but it seems that it is not recognized as a USB → COM port.
It’s listed as an unknown device in device manager.
Should this be considered as one of the chips on the board has broken?

Also, I feel that the temperature of the chips mounted on the board is strangely higher now than I was using at the beginning.
(It is very hot.)

Could you let me know if there is anything else I should investigate?