Question New Built PC will not boot by a modular PSU but can boot by a semi modular PSU

[Kappa123123123]

All parts were purchased brand new
i9 14700K
ASUS ROG Maximus Z790 Dark Hero
G.SKILL Trident Z5 RGB Series (Intel XMP 3.0) DDR5 RAM 64GB (2x32GB) 6400MT/s
HX1500i

I have a CX750M PSU which can boot the PC, a HX1000i that cannot boot the PC, and a brand new just open HX1500i which cannot boot the PC too. Both of the HX has tested with a paperclip and both of them can jump start. Why the PC can only turned on by the semi modular but not the fully modular?

 

[helpstar]

Did you connect both ATX connectors bottom right to the PSU? the 24pin ATX connector to the motherboard is split into 2 connectors, one 10pin and one 18pin

https://gzhls.at/i/85/19/2768519-l0.jpg

connect the the two 8pin EPS/CPU connectors to the motherboard and PSU as well

don´t mix cables of PSUs, could be not compatible to each other

 

[Kappa123123123]

Did you connect both ATX connectors bottom right to the PSU? the 24pin ATX connector to the motherboard is split into 2 connectors, one 10pin and one 18pin

https://gzhls.at/i/85/19/2768519-l0.jpg

connect the the two 8pin EPS/CPU connectors to the motherboard and PSU as well

don´t mix cables of PSUs, could be not compatible to each other

I did connect both of that and it still cannot boot.

 

[helpstar]

please take some pictures of the connections, maybe we can see something odd like faulty connectors or similar
upload to imgur.com

any q-code shown on the motherboard?

 

[Kappa123123123]

And there is no code