Some info about my hardware:
I own a X299 FTW K board with an 7920x and a EVGA 1070TI GPU in PE2.
First Add on card pcie creative soundblaster. (in PE1)
Second Add on card pcie usb 2 (for my keyboard which only works well on true usb2)(in PE6).
4stick of 4GB Corsair RAM
Now the problem, like subject says my system sometimes shows a single letter code in the screen. Just a C
This happened in the past week for the first time.
Also it only happens when I turn off the system (W10 PRO) and after a minute or so the system powers up but not fully it seems. cause it is stuck at error code C and no graphical output.
I have to then force it off with the power button.
The manual has no statement what a code C is.
This error code happend for the first time after installing the usb 2 and sound card.
Maybe the EVGA team knows what it is or a member.