Question Issue with power LED

[Lodestar 1]

Wonder if you can help with troubleshooting a new build.

Corsair Carbide 100 case with Gigabyte B450m DSH3 motherboard. Connected front panel cables and when powered up the LED power light does not come on. I then switch around the + and -,connections on the front panel slots on the mobo and the power LED is ON but only when the PC is powered OFF. When l power up the PC the LED power light goes off..

I have not yet looked at the BIOS but could the issue be resolved through a setting there?

Thanks for your help.

 

[ElectrO_90]

Are you sure you have connected it correctly?
It shouldn't do that unless you have power going in the wrong areas/connected incorrectly.

 

[Lodestar 1]

Thanks for the reply. Connections into front panel sockets on motherboard are correct l have triple checked. 24 pin power is correct and CPU power is correct. It is powering up ok all fans working etc.

Any other ideas?