You have to ask Evariste for the password, don't know how they are different between devices or firmware. My device reported a fw version and a hw version prior to bricking. But as debricking resulted in also deleting hw version, I really don't know which version you would need. Sorry about that. At least, if your device looks like mine you would have the possibility to get into it by serial. On the other hand, telnet will give the same information if it is working. So best advice: don't brick it and ask Evariste, the wizard!
With the new Pluto firmware from Evariste, F5OEO, Pluto, H.265 encoder box and OBS settings can be changed on the fly and simultaneous. So I recently ordered one of these boxes, but could not upload the firmware patch. Turns out this box has different firmware (ENC_V2.41.201231 instead of ENC_V2.38.201216). Evariste kindly offered to try to upload via internet. However, during this venture he accidentally bricked the device. Communication via its ethernetbus was not possible anymore. An internet search revealed that the main device (Hi3516) should have a serial monitor. However, was it brought out on the board? Probing with a voltmeter and a logic analyzer revealed indeed a signal resembling a 115200 baud serial tx on an unused pad on the board. Hooking it up to a PC via a level converter (3.3. to 5V) and a serial-to-USB adapter showed a typical linux startup on boot. It also reported a missing file and not able to start the application. Also the http-server did not start up and the device did not use DHCP anymore. So IP-address had to be modified by hand, which was succesfull in the end.
Here Evariste took over and was able to re-install the firmware and add the patch over the internet. So the device was unbricked and works again, although further tests have to be performed.
By the way, not only the firmware, also the hardware is different between these devices. Jaap, PA2JSA kindly sent me a picture of the board of his device with the .38 firmware and that differed significantly from the one shown below. Although the main device, the Hi3516 is the same.
In the picture below the two wires above the Hi3516 are TX (as seen from device) on the left, RX on the right. Third wire is ground. Level is 3.3V.
Hope this might be helpful for someone struggling with a bricked device.