Quote from: ccgllc on April 18, 2019, 01:30:28 AM

Which is not true. You can downgrade via the sdhc card as outlined at the Bitmain site. We have down well over 20 downgrades without a hitch, more almost every day.

https://support.bitmain.com/hc/en-us/articles/360019493654-S9-series-S9-S9i-S9j-S9-Hydro-Control-Board-Program-Recovery

Hey ccgllc, I just mistakenly installed the new 2019 firmware on my antminer S9. I am also pretty sure I blew out a hash board in doing so as well. I installed the T9+ toolkit and moved the 4 jumper to the right position. Miner still isn't booting off the SD card. I am only running 2 hashboards at enhanced lower power now. I am running 110V power from the wall on a 1850W PSU. How can I troubleshoot the hashboard and how did you boot the S9 miner from the SD card?