Before system only reset over web UI: static IP, ssh opened
After system only reset: yellow solid LED (but sometimes after reboot becomes blinking yellow)
40 seconds reset does not seem to work (since after releasing the button the system does not seem to reboot)
What should I do now?
if you can ping it may be possible to flash the firmware using TFTP. this can be a little tricky though.
Have a good read through this post, hopefully it can help you.