Question PC case fans aren’t spinning, CPU & GPU fan spins though no post? (What’s Wrong)

[MutualBenefits]

So, the question I was wondering after rebuilding my pc with a new motherboard and PSU, why are the case fans spinning then stop though GPU & CPU fans work plus motherboard RGB works. With this issue I’m not getting display (no signal to my 4K TV)…. The case fan cords have three holes to plug into to the CHA_fan areas that are 4 pins.

Ryzen 9 5900x on Asus Tuff gaming x570 pro Wi-Fi II
64GB DDR4 Ram (16GB * 2 @ 3000 / 16GB * 2 @ 3200)
Nvidia GeForce RTX 2080
Samsung Evo 870 512GB
Crucial ITB SSD
4TB SeaGate HD
Corsair Rm1000x PSU

 

[Lutfij]

You might want to stop mixing and matching two different ram kits. Of those two, remove the DDR4-3000MHz ram kit and work with the DDR4-3200MHz ram kit. As of this writing, what BIOS version are you on for your motherboard? To add, what are the makes and models of the fans? You might want o parse images of what you're referring to as connectors since we've seen people connect the wrong devices into the wrong headers to end up with a dead system.

 

[JohnBonhamsGhost]

CPU & GPU fan spins though no post?

if you're not getting any display output then you have no idea if the system is POSTing or not.

the system not being able to POST and you not being able to view the POST screen are two different issues.

why are the case fans spinning then stop though GPU & CPU fans work plus motherboard RGB works.

your BIOS could be set by default to run in a quiet mode
where fans will spin down to 0RPM with low temperatures,
or it could be set to a DC mode with low voltage % that is not enough for your fans to continue operating.
once these these types of profiles were loaded the fans may stop.

or the fact that they are 3pin fans and the BIOS is set to a PWM profile a conflict may occur regarding voltage vs RPM value.

case fan cords have three holes to plug into to the CHA_fan areas that are 4 pins

does the case have it's own integrated fun hub that offers 4pin PWM out?

what case is it?