Ubiquiti Airrouter serial connection for unbrick via console

Here is how to open up an AirRouter-HP from Ubiquiti, and connect up a TTL serial cable to the motherboard. This is only needed if you brick your device by trying to upgrade it, and the consumer interface (long reset button presses) are no longer working. It is also useful if you just want to see the console statements on bootup for troubleshooting the device. Note, opening the unit up, will void your warranty so tread carefully. If you are out of warranty anyway, it doesn't matter. the pins for the serial connection are 3 and 9, with ground on 11 pins are numbered like this: 1 2 3 4 5 6 7 8 9 10 11 12 and pin one has a little arrow pointing at it, at least on my board. Baud rate should be set to 115200 N81 and hardware flow control OFF I also show how to test a simple loopback method, to verify if your serial connection is working properly or not. If you encounter the problem on a Bullet or Titanium, the fix is the same, but the uart header is 4 pins and tx rx are the middle 2 pins, ground is on the end nearest the antenna connector. Baud is 115200 If you try to push 3rd party firmware and brick your unit, it's likely because AirOS 5.6.2 and later uses a different partitiontable and bootloader. Once connected, break the boot sequence by hitting esc. from the prompt, enter these commands to restore the old boot loader, (pre 5.6.2) urescue -f -e use tftp from a 1.20 connection and push older firmware like 5.5.1.1. power up again, break the boot sequence, enter urescue, (no flags this time) and tftp the same 5.5.1.1 again. Now power down, button up the case, and hold reset while powering up, wait for TFTP mode by the wigwag lights, and tftp the firmware that you want to use, 3rd party, AREDN or whatever. 73 de AG6IF