CNCFAN part in hotmode v.1 board doesn't work

[Moreirao]

My 2 fan parts doesn't work
I tested continuity in motherboard.

I changed the original fan to new o 4020 24v fans and I accidentally touched wrong the multimeter to the cncfan port to test the voltage and boom I burned the plate (I think so because the original fan stopped after some sparks). The other extruder components are still working ok (like the video below) but the fun parts no. So I bought a new hotmode board v1.0, but the fan parts are still not working. When I send the M106 command or by TFT the fan parts does not work. Originally the new 4020 fan part was inverted cable and I changed and tested them in the extruder fan2 port.

I tested the b340a diode with multimeter and ok
I put recently the marlin 2.0.9.1 with BL touch changes and TFT35_B1_V3.0.27 firmwares in my Biqu B1 SKR 1.4 32bits

[radek8]

[albertovm]

I have the same problem. No 24v in CNC Fan.
I have (variable) voltage in CNC Fan cable that connects in to board A. Voltage control works using B1 touch display. I dont have any power only in board A.
However, I tried another "B board" from my Biqu B2 hotend, and I have the same problem (no power out for CNC Fans).
It appears to be a problem in USB cable or board A.
Is there anything in board A that could stop working? Is there any way to test the USB cabe?
Thanks.