[Solved] How to unbrick a RouterBoard 750(G)

I’ve managed to make not one but two RouterBoard 750 (one 100Mbps and one 1Gbps G-version) into paper weights and according to all the docs I can find on the wiki, I need the serial console to them back into a working order. Unfortunately, this model does not feature serial ports.

Is there any way except serial ports to replace the OS? Only one is bricked because of bad firmware upgrade, the other does not have any IP-address on the LAN-side, and administration is blocked from the WAN-port.

Opening the box, I could find a couple of different testing/soldering points, so I’m hoping that two of these are RX and TX, either TTL-levels or RS232-levels. Attached are pictures of the points.

Of course, I would be much happier if I didn’t have to solder on the circuitboard, and some other solution was available.
RouterBoard 750G.JPG
RouterBoard 750.JPG

I don’t have any 750, but you could use WinBox to gain access to the one with a working RouterOS. You’ll need to use it’s mac address, because there’s no IP address to access to.

Regards

you can also try the method that’s recommended in the manual. hold the button to start Netinstall. check PDF manual in routerboard.com for details

I did also managed to brick one of mine RB750.
Just did the netinstall (RTM) and it works again!
No need for serial :slight_smile:

An RTFM-session and a XP install later and I’m (more) in love with RouterBoard.

Worked like a charm, and sorry for the RTFM question.

Those points on the board are definitely not serial, as that would show up in winbox even without the serial port connector. They are more likely something like jtag or lpc to program the flash at the factory.

If you look at the components, there is no max232.
So if it was serial you would need a TTL converter.
And it not showing up in /system/ports can be scriptet.
The price of the RB750 is just nice, so it not having serial is no problem :slight_smile:

Actually the problem would be greater if it WASN’T TTL, because then I’d have to solder a connector instead of just hooking it up to the FTDI “debugger” (printf is the ONLY true way of debugging :wink: )

Too bad about it not having a serial port though, but the reset + netboot worked perfectly, so no complaints here :smiley: