This guide will show you how to bypass “Can’t Find Signature” when updating Antminer S19 firmware.
When you see Bitmain Antminer S19 Backstage Shows “System Upgrade Failed: Unable to Find Signature!!!” always means the firmware you are upgrading is not a security firmware.
This issue, which still affects all BTC miners, is what we will discuss today.
Note: This operation carries some risk, and you are responsible for any consequences.
Read more: Bitmain Antminer S19 Series Can’t Upgrade Firmware/firmware Upgrade Failed
The specific operation steps are as follows:
1. You will need to use an SSH tool like putty;
2. Enter the IP address of the miner in putty and reserve port 22; if a message pops up, click Yes;
3. Enter the miner page with the credentials root and admin.
4. Copy and paste this line of code;
Code:
cd /www/pages/cgi-bin
After the input is complete, press Enter; you will see the following page:

5. Enter the following;
Code:
vi upgrade.cgi
6. Use the down arrow and find this code;
Code:

7. Click “i” on the keyboard to enter edit mode;
8. Change the code in step 6 to this code;
No code needs to be changed or added; more details are provided in the comments below the code.

Note: Add # to the first 15 lines and remove # from the following 5 lines
The miner will only ignore the IF function searching for the signature if you add a #, which indicates that the line is commented and won’t be executed.
Press the keyboard’s ESC key (exit) while editing the code.
9. Input
Code:
:wq
and press Enter to upgrade and save the file.
10. Input
Code:
:q
and press To save the SSH session, press enter.
11. Flash the updated Antminer S19 firmware.