My father had previously purchased the Asus z590-e strix motherboard. It was having an issue, so he recently bought another Asus Z590-e Strix motherboard. He's running into a issue that the board would not post. The board was doing the same thing before. It would turn on but the board would not POST. The board is stuck on code 99 but the keyboard and mouse are connected to the usb 3 port.
Unfortunately this error code it is a big flag and can be one of many things and POST will not advance till the hardware issue is resolved.
Qcode 99 is "Super IO Initialization" and IO meaning anything connected to the board by any interface is not initializing.
If you have just built the system, then it is saying a device is not connected properly or there is a lack of power to a device causing the IO error.
First check all cables and components are seated flush and level and aligned in parallel with Pci-e slots and your DIMMs seated correctly.
Should the condition continue, you will have to Bench test outside the case and reapply your TIM after checking for bent pins. Test with a minimal configuration then add components till you post successfully or identify the failing component.
Is there a reason the initial board was not RMA instead of buying a new one.