Hello Vilius,
For full clarity, I will try the process again and describe it here.
I connected the laptop and the router (LAN port) with an Ethernet cable.
I pressed and held the reset button, powered the device on, and kept holding it for 4 seconds.
On the laptop, I configured an IP address from the 192.168.1.0/24 network and opened http 192.168.1.1
in the browser.
I got the recovery page:
FIRMWARE UPDATE
You are going to update firmware on the device.
Please, choose file from your local hard drive and click Update firmware button.
I downloaded the firmware RUT9XX_R_00.06.09.5_WEBUI.bin (since my problematic Teltonika version is RUT950 HG12C0, this is the latest firmware) from:
/view/RUT950_Firmware_Downloads
Until uploading the firmware, the LAN LEDs were blinking rapidly, about 3–4 times per second, and the GSM LEDs were off.
I selected the firmware file and started the update (or rather, recovery).
At the same time, I ran ping 192.168.1.1 -t for visual diagnostics.
After starting the firmware update, I saw:
Your file was successfully uploaded! Update is in progress and you should wait for automatic reset of the device.
Update time depends on image size and may take up to a few minutes. You can close this page.
ICMP monitoring:
Reply from 192.168.1.1: bytes=32 time=1ms TTL=128
Reply from 192.168.1.1: bytes=32 time=1ms TTL=128
Reply from 192.168.1.1: bytes=32 time<1ms TTL=128
Reply from 192.168.1.1: bytes=32 time<1ms TTL=128
Request timed out.
Request timed out.
Request timed out.
Reply from 192.168.1.111: Destination host unreachable.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Reply from 192.168.1.111: Destination host unreachable.
Request timed out.
Request timed out.
Reply from 192.168.1.1: bytes=32 time=3ms TTL=64
Reply from 192.168.1.1: bytes=32 time=2ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64
During the update, the LEDs blinked slightly slower for about 3 seconds and then returned to fast blinking.
After that, the router rebooted.
After booting, the LAN LED and GSM LED are blinking (green/red).
There is no standard login page.
I cannot access the router.
An SSH session can be established, but default credentials do not work:
root/admin01, admin/admin01
This was an attempt to recover the firmware.
Regarding the bootloader update attempt:
The page opens: http 192.168.1.1/uboot.html
I do not have a bootloader image.
I honestly spent an hour trying to find where to download it.
The instructions here:
/view/RUT950_Device_Recovery_Options#Bootloader_menu
say that the bootloader can be downloaded here:
/view/RUT950_Firmware_Downloads
Unfortunately, I could not find it.
Could I please ask for a direct link to the bootloader image?