921 front usb not connected but in my pc they work

[eliiid]

so i changed my pc hp prdesk 400 g1 mt case with atx manhatten but when try to open the pc it say 921 front usb not connected but in my pc they work fine

 

[George Phillips]

USB ports fail sometimes due to many reasons. It's quite possibly that the USB port on the front panel has failed. The other reason could be that it's not connected. Check the connector of the front USB port. It must be connected to the motherboard.