hot end /nozzle not heating
I'm facing a tough time with my Creality 10 s PRO.
the hot-end do not heat anymore. Bed is Ok. I got a new hot-end one -> the temp displayed is -19°C, change it today to another one it displays -15°C
I used a multimeter to check whether power id provided. answer is 0 V - (plugged on the two red wires).Therefore I'm thinking that it could come from .... the motherboard?
Is there anything I can check before moving to that expensive option ?
Thx in advance.