Please need help, P400A a fan doesn't spin

[sowhat]

3 fans are plugged into motherboard, but only a fan doesn't spin, what's wrong?

 

[Bill_Bright]

Sadly, you gave us nothing to go on. I assume P400A is an Phanteks case but case fans are pretty standard. But without knowing the motherboard, or how you connected the fans (assuming you don't mean the CPU fan too), or anything about your PSU or the remaining devices, or even if everything else works fine or not, we can't help you beyond verifying everything is connected properly.

Please fill out your System Specs and tell us what happens when you boot, then maybe we can help you.

 

[sowhat]

3 fans connect to the motherboard but only one fan can't spin.

I try to plug into other fan connector on the motherboard, but the result same.

I'm using B550 msi motherboard.Is it motherboard issue or the case's fault?

 

[Mr Bill]

3 fans connect to the motherboard but only one fan can't spin.

I try to plug into other fan connector on the motherboard, but the result same.

Have you tried to plug in one of the working fans, into the same fan connection on the board, that the non-working fan was plugged into? I would do this, and if one of the other fans work, I would say you have a dead fan.

 

[Ramo1203]

Check the case manual, your case seems to have a fan HUB. In that case (no pun intended) you usually give power though a SATA cable to the hub and then connect the fans to the hub directly (you can change the fan speed with a switch on the case). You can also decide to directly connect the fans to the motherboard.