Hi,

Unfortunately there is another type of board. I tried boot from SD several times but immediately after I switch jumper 4 to boot from SD position I got both leds green + red constantly on and nothing happen. After some google investigation I found that my board is missing some chip close to slot as you can see in images :-(

I ordered CP2102 UART to USB (https://www.aliexpress.com/item/1859102520.html) and hope that I will be able enable SSH on secure firmware or boot from tftp to remove secure firmware from my board.

Image 1 - Antminer S9 control board Ctr_C41 Vers: 1.20
As you can see there is some sticker with some chinese + TF Card
https://pasteboard.co/InjoGnE.png

Image 2 - detail of missing chip ..
https://pasteboard.co/InjppJn.png

Will add more information after converter arrive.

Thanks and regards,
MK

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Hi,

I prepared guide how to enable ssh on secure firmware via serial console for those without functional SD card slot. I will also add steps how to unbrick antminer without sd card slot.

https://docs.google.com/document/d/e/2PACX-1vSu6XGV4Q40TerRPccB7xxTf2sKNkp1Bkwkdz4ILhIaa9qaT-NvZWtFrIBiwpRsG3NRlzvwQkbKyvsv/pub

Thanks and regards,
MK