Jetson Nano No Response

Im new on jetson,when i want to restart the jetson before install system,i just truned off the power and when i tried to turn on it,no screen response and also no keyboard response.
Green LED and my jetson case’s power LED is on,the screen has no signal.
Also i used the RESET button(i think on GPIO is RST) and still no any response.
pls i need help

You would have to provide a serial console boot log to see what is going on. Alternatively, if it is just the display not working, you could log in via ssh and get the dmesg log. Serial console is always the recommended debug tool for logs. See:
https://www.jetsonhacks.com/2019/04/19/jetson-nano-serial-console/

Perhaps it is just display? On the other hand you should never stop a computer by just pulling the power or hitting the reset button. The ext4 filesystem has a journal to prevent corruption (unless the data involved exceeds the journal size), but a replay of a journal essentially removes content which had been cached and not flushed to disk. You will lose content with journal replay even if the filesystem is technically not damaged (content on a filesystem is separate from whether the filesystem itself is not corrupt).

i dont know how to serial console boot log and there,and idk how to connect to ssh(i have ssh tool but idk the passwd and username)
and the screen has power but no signal.
ty very much

The URL link I gave above is information on how to use serial console for logs.

Do you have another Linux computer on the same network as the Jetson? If so, then ssh is simple. By default the micro-USB cable would provide an IP address of 192.168.55.1 for the Jetson when connected in most cases. If the wired ethernet is connected to the same router as the host PC, then this too would assign an address (but you’d have to figure out from the router what that address is). If the user name you log in with is “user” (just an example, adjust for your case), and if the address 192.168.55.1 is visible from the host PC, then ssh login would go like this:
ssh user@192.168.55.1

The above would lead to a text command prompt. First login would probably ask if you believe the connection is legitimate. You would have a command line prompt and simply run the command “dmesg”. Copy and paste that and post here (highlight this with your mouse in the forum and mark it as “code” via the icon “</>”).

no i cant cuz i input the lan and the lan’s green led is not working(either the orange one)
also i cant find the address from the router.

@linuxdev already shared how to dump serial console log in previous comment. I don’t know why you still don’t know how to dump.

Please be aware that if you keep saying that “I don’t know” or “I cannot” without really sharing useful info, then no one is able to help you.
If you don’t know something, then please share us which part in the tutorial that you cannot understand.

yes ik this,but i dont have the Adafruit USB to TTL Serial Cable
can i do this with anothor way?

No, this could be only done with the help of those devices.

A serial cable is relatively inexpensive, and very very useful for anyone developing on any embedded system. I highly recommend having this, but there is perhaps one other way if and only if the system is actually booting and the only issue is the GUI: Use CTRL-ALT-F3 and see if you can reach a command-line-only prompt. You’d have to give the Jetson plenty of time to boot as the prompt would be one of the last things made available during a boot. This prompt is not the best access, but it does allow logs to be examined, and (should it work) the output of dmesg would help.