Remora - ethernet NVEM / EC300 / EC500 cnc board

Hello scotta, you are such a great programmer.
These days, my NVEM V5 RT1052 control card cannot connect to Mach3, and then I found your post on building linuxcnc on Google. The post shows how to flash Remora firmware on NVEM V2. I spent two days reading the entire post of 230 pages.
But since this is not my specialty, it took me two days to install debian12 linuxcnc.
I also want to revive my NVEM V5. I want to embrace linuxcnc and abandon Mach3. I need your help. I now have two ST-LINK V2, exactly the same. I changed how to flash Remora in the first step. After the V2 soldering pins are connected to ST-LINK, the control card does not light up the signal light as you showed on YouTube. It must be connected to 24V power supply.
I found that many people mentioned this problem in the 230-page reply. I hope to get your help. I want to record the whole process as detailed as possible and then show it to those who need it.