Thank you for your reply.

Could you please link me to an old version of NAND recovery that did not verify the signature?

Also, about someone who spoke about the bad habit, I should tell that the FPGA control board is from AntMiner company and its NAND model is the same as other AntMiner devices. Please see the AntMiner brand arm on the back of the control board: https://zeusbtc.com/articles/asic-miner-troubleshooting/1757-how-to-remove-viruses-from-the-antminer-l3-control-board

Hi everyone,

I do have an FPGA F1 mini plus miner from HashAltCoin.

Its NAND firmware was recovered by this file:
https://file12.bitmain.com/shop-product-s3/firmware/4107882a-8be1-4484-940e-bd402d7c0bb0/2022/09/26/14/201904231534-L3%2B-SD-recover-NAND.zip

Now, I can not flash the original HashAltCoin firmware for this miner which is available on the:
https://firmware-1256910030.cos.ap-hongkong.myqcloud.com/firmware/20200621/upgrade_altcoin_F1-MINI%2B_rootfs.tar.gz

Because I got a signature error message when I want to flash it!

Also, I can not connect to its SSH port via Putty because the TCP(22) port is not open on my miner!

So, How can I flash my F1 mini plus miner with its original firmware?

Thank you all.