Console rotates through all tty's after sitting for a bit

[Warren Block]

On Thu, 21 Jan 2016, Malcolm Matalka wrote:

> Polytropon <freebsd at edvax.de> writes:
>
>> On Wed, 20 Jan 2016 10:11:24 -0700 (MST), Warren Block wrote:
>>> On Wed, 20 Jan 2016, Malcolm Matalka wrote:
>>>
>>>> I installed FreeBSD on a machine (Dell OptiPlex 7010).  I'm in the
>>>> regular text console and if I just leave it, it starts rotating through
>>>> all the tty's rather than going into a screen saver or anything (I have
>>>> explicitly set the screen saver to a Blank screen).  It did this during
>>>> the install process as well.
>>>>
>>>> Has anyone experienced this and know why?  It doesn't seem to
>>>> negatively affect anything so far, it's just annoying.
>>>
>>> Something is hitting the PrintScrn key.
>>
>> My first thought exactly. :-)
>>
>> Check the physical keyboard, and if it is a wireless keyboard,
>> check possible "offending" other keyboards of that kind, too.
>
> Interesting.  It's a wired, but USB, keyboard.  The keyboard itself is
> in Swedish but I am using an English (US) keymap.
>
> I'm curious though, why would this happen after sitting for awhile
> instead of all the time?  Just random keyboard driver freaking out after
> idling for a bit?

Could be a driver bug, but that seems unlikely.  Could also be hardware 
causes.  kbdmux(4) combines all keyboards, so it could be another 
keyboard or even a USB device that pretends to be a keyboard.  Could be 
a failing keyboard, a bug in the keyboard firmware, or a cat that likes 
to play with the PrintScrn button.  The sufficiently paranoid might 
wonder about hardware keyloggers.

I'd start by swapping out the keyboard to see whether the problem moves 
with it.  The replacement should be a different brand and model in case 
it is a firmware bug.