Boot error

[SeekaX]

For about half a year now my PC randomly gets stuck with a 9C or A2 error on boot. It used to happen about once a month but recently it has been happening more frequently so i am somewhat concerned that my board may be on its way out. Usually a restart fixes it, but today it took three attempts. A quick google search suggested that the 9C error is related to the USB ports and A2 is for IDE errors, however i can't figure out the cause since it doesn't happen consistently. Any ideas?
Relevant specs:
MSI Z87 MPOWER
i5 4670k
4x4GB 2133MHz 9-11-11-31 1.65V Corsair Vengeance Pro
Everything stock with enabled XMP profile. USB devices are just the standard stuff, mouse, keyboard, amp/dac and a usb soundcard i use for my mic.

 

[Excalabur50]

Just a thought how new is the bios and try swapping usb to different ports and maybe the sata to a different port too and see if that stops it

 

[AlienALX]

It could just be something you have plugged into the USB port that causes issues. I had a keyboard once that would stop me being able to access my bios (would freeze on the way in). Took me bloody ages to figure that out too !

Try removing the AMP DAC and anything other than the KB and mouse.

 

[SeekaX]

The BIOS should be from 2013, haven't updated it since i bought it. What keeps me from blaming any of the USB devices i have is that the boot lock only happens once in a while and it only started occurring roughly half a year ago, but my setup hasn't changed in 1.5 years.

 

[AlienALX]

Try and update the bios dude. Especially if you got the board close to launch, because early bioses are a pig.