Thank you very much for the answer! If I leave the TX clear on the Router the port LEDs wont turn on and I just see a orange light. I kept the 4 key pressed on my computer which is running the
screen session and then connected the TX of the router to the RX of the console after ~15 seconds, but nothing is happening at all. When I keep pressing the 4 key the TX LED on the console should blink (?) but it's doing nothing.
EDIT: Ok problem solved.... listened to the wrong tty -.- Thank you agian for the help!
EDIT2: So now I'am stuck again with a bricked device... I used the firmware listed here: https://downloads.openwrt.org/snapshots/targets/ramips/mt7621/
Where can I get a stable version of openWRT?
EDIT3: Even the stable image from August ist crashing:
[ 4.624339] [<80549cc4>] 0x80549cc4
[ 4.627807] [<80549248>] 0x80549248
[ 4.631274] [<80476c4c>] 0x80476c4c
[ 4.634744] [<80476c5c>] 0x80476c5c
[ 4.638213] [<80476c4c>] 0x80476c4c
[ 4.641680] [<8000afd8>] 0x8000afd8
[ 4.646757] ubi0 error: 0x802e7530: failed to erase PEB 939, error -5
[ 4.653192] ubi0: mark PEB 939 as bad
And now it crashes here:
[ 0.387638] futex hash table entries: 1024 (order: 3, 32768 bytes)
[ 0.393933] pinctrl core: initialized pinctrl subsystem
[ 0.399756] NET: Registered protocol family 16
[ 0.410003] Can't analyze schedule() prologue at 80478bc4
[ 0.416100] pull PCIe RST: RALINK_RSTCTRL = 4000000
[ 0.721346] release PCIe RST: RALINK_RSTCTRL = 7000000
[ 0.726379] ***** Xtal 40MHz *****
[ 0.729752] release PCIe RST: RALINK_RSTCTRL = 7000000