Thank you for your reply.
Just tried it with other power supplies. It won't boot up. LAN light is on.
I think the bootloader or the flash memory chip is damaged.
The voltages I found on the board are as follows:
1V, 1.25V, 1.65V, 3.3V, 5V, 19V.
Maybe someone has a NAND dump. I can flash the...