Hardware upgrade

I have new RB493AH. I’ve upgraded OS to 5.5. All goes fine, but then I’ve upgraded routerboard by command:
/system routerboard upgrade

After this i can’t enter to RB by WinBox.
Any suggestions?

Hook up a serial console and see what’s going on.

Serial console? Can you post wiki page or something, because i’m new in mikrotik)

http://wiki.mikrotik.com/wiki/Manual:First_time_startup#Serial_Cable
http://en.wikipedia.org/wiki/Out-of-band#Computing

Thanks a lot.

115200bit/s, 8 data bits, 1 stop bit, no parity, flow control=none by default.

That’s the info I was looking for