Quote from: technak on July 17, 2019, 08:28:51 AM

Hi,
MigaoMiner: I had exact same problem, because my board is just missing chip for sd card. With this method you dont need boot from sd card. Just keep jumper in default position, connect uart bridge, disable ssh as described and then you can install another firmware like braiin os.

Jacoob007: as far as I know this is not possible at the moment. We can just hope that bitmain will change their minds and in next fw we will have option to enable ssh ...

There have been at least two releases in 2019 for S9 firmware from Bitmain and both are "signed" with ssh access closed.

There is a method to restore ssh access using an exploit in the first release. If you have installed the second release, it is possible to "downgrade" back to the first release, since both firmwares are signed. Then with the first release you can try the exploit. This uses proprietary code but is one way to restore ssh without physical access.

The other methods involves using the sd card, or using the serial port. Both require physical access.

The serial port method is a little more involved, and requires either the rj45 to serial cable or using the 3 pin header to serial. Then you can manually overwrite portions of the nand using an sd card; or manually remove the signed firmware check so you can downgrade or install another firmware.

Normally people would just use the sd card method, where this is done automatically when moving jumper jp4, but i guess you may encounter the issue of that missing chip mentioned before...

With the sd card method you force the old T9+ firmware, which in turn allows reinstalling the old S9 firmware (you can't just leave the T9+ firmware because it doesn't hash anything with that).

OR, you can boot Braiins OS from the sd card and optionally install that from its Web UI instead.

Ok lets summarize this:

Remotely via software (closed source):

ASICseer security-restoring-ssh

Physically using:

TF (microSD) card:
- S9 series (S9, S9i, S9j, S9 Hydro) Control Board Program Recovery
- Braiins OS

Serial port:
- Rescuing a bricked T9 (and S9?) Control Board - HOWTO
- Antminer Hack S9 /S15 / S17 / Sx aso. SSH and so on for free