Question Sometimes all USBs are dead until OS boots

[mrwolf33]

Since right after I installed a new GPU (RTX 2060, with a PCIe riser) I am having problems using the USB keyboard during BIOS post or even at the bootloader menu (Windows/GRUB2, same).

I also tried using no hub and using the USB2 or USB3 ports of the motherboard, same effect: USBs stay dead until the Windows or Linux kernel boots up. This is a big issue if I need to use the bootloader menu or the BIOS, as I have to try my luck plugging/unplugging the USB to hope it maybe starts working.

I have tried with a different keyboard, same result.

My questions are: has anybody ever experienced something similar? I have not tried unplugging the new GPU to see if problem disappears, but even if it would: can a new GPU cause this? Is the motherboard USB starting to fail?

Motherboard is ASRock B85M-ITX by the way.

PSU is a be quiet! L8 500W bought in 2016

 

[Ralston18]

Update your post to provide full system hardware specs and OS.

Include the PSU (make, model, wattage, age, condition).

Doublecheck all internal connections and seatings to ensure that all are fully and firmly in place.

And do try unplugging the new GPU. If the USB keyboard problem stops then that may indicate that the new GPU is directly the cause or, more likely, presenting additional power demands that the PSU cannot support.

Keeping in mind the power requirements, If at all possible try the new GPU in another computer.

Determine if the problem follows the new GPU.

 

[mrwolf33]

@Ralston18 your troubleshooting procedure is impeccable, however I do not have another computer around to do a test right now, so that part of the test might be delayed indefinitely for now.

I will do some tests and then update the post with more information about the setup.

 

[evongugg]

Do you have the latest bios installed?

https://www.asrock.com/mb/intel/B85M-itx/#BIOS

 

[mrwolf33]

Detaching the PCIe connector would make the USB work as intended.

Do you have the latest bios installed?

https://www.asrock.com/mb/intel/B85M-itx/#BIOS

I have installed the latest version and problem is gone.

Perhaps the BIOS was starting the USB in high power mode which was not available due to the new GPU drain from the motherboard.

Both the old GPU and the new GPU have an 8-pin power cable so I could not think that they were still draining a lot from the motherboard.