Tl 494 power supply/welder

[Merces]

Hello!
I stated working on an TL494 SMPS inspired by an video i found on youtube.
I design and made the pcb for it in easy eda and each the pcb. today i soldered everything on the pcb.
i powered up the control circuit, but nothing. no output signal. i checked the voltages and they are ok.
can anybody tell me what is wrong?
Video:

/>Original schematic: https://i.ibb.co/my9NCzf/50v40a-power-supply-and-arc-inverter-welder-By-devreci.png
My versions: https://oshwlab.com/No_op-amp/smps

[John123]

Hi, I'm not an expert on this stuff but is there any way you could trick it into running open loop with the main transformer disconnected just to check if you get a switching waveform at the outputs of the TL494?

[johnf]

The video made me seasick
too much movement
but
what are the exact cores you have used for the transformers ie the mouser, digikey, element14, part number
The 40:9:9 transformer does not look big enough