We have TX2 which was working properly, we didn’t use it for 1 month. after that tried to power it but it shows a black screen. the screenshot for the serial consul is in the link bellow, is it a hardware issue?
mmcblk0 is the eMMC, and this is an error. It isn’t possible to say from that if it is hardware or software as either could do this. A full boot log would be helpful, and serial console programs can log (I use gtkterm).
I don’t know which release you are using, but a good test would be to see if you can successfully clone the rootfs partition. There are other partitions, but it wouldn’t have made it that far unless the boot stages completed. The correct clone procedure depends on release, and does take a lot of disk space on the host PC.
If you don’t mind overwriting your rootfs partition and losing its content, then you could simply see if flashing it works.