On Tue, 2017-10-10 at 14:17 -0500, Nicholas Geovanis wrote: > On Sat, Sep 23, 2017 at 7:48 AM, Roberto C. Sánchez <robe...@debian.org> > wrote: > > > I had this exact same problem with Jessie on an HP ProBook 650. The bug > > was in X.org and was fixed when I upgraded to Stretch. The problem, as > > I recall, was that certain display hardware inverts the sense of the > > intensity, so that instead of it going from 0 (dark) to max (bright) it > > goes from 0 (bright) to max (dark). X.org sets the display brightness > > to what it thinks is max on the log in screen to compensate for the > > possibility that was turned all the way down by a previous user. > > > > What I found as a "workaround" was that I could log in as normal and > > then by using the brightness control function keys I could increase the > > display brightness after logging in. > > > > Just confirming that apparently I had this same issue with jessie 8.4 on > Dell hardware. > The problem only occurred if a second monitor was connected prior to boot. > Only the > second monitor's brightness was dialed-up at boot, the primary (laptop) > screen would > be dialed down to 0 brightness. Unfortunately the login prompt was on the > laptop screen. > Simply dialing-up the brightness was the fix, but it took me a while to > realize it.
I experience this bug in jessie as well. However, that bug got fixed in stretch. The bug I'm now facing is random (short) periods of a black/blank screen. Just as anxiousmac nicely summarized said before: On Sun, 2017-10-08 at 04:42 -0700, anxious...@gmail.com wrote: > I have exactly the same problem with the same model of laptop ( HP EliteBook > 840) > > > From time to time the screen goes blank for 2-6 or so seconds. Pressing > > random keys may accelerate return, it's hard to say. Certainly those key > > presses appear to be acted upon in whatever window has the input focus. My > > BIOS is the most up to date one from the HP website. > > It's irritating but not a show stopper. Would be nice to know how to > investigate. On Sun, 2017-10-08 at 04:05 -0700, Jimmy Johnson wrote: > Can you see the position of the screens? Maybe install package "aranr", > it's a small GUI to setup the screens. I will try this, although I'm not exactly sure how this would help as 90% of the time the screen display works fine. By now I also have a bit more experience with switching to a virtual console when this occurs, but alas, this doesn't seem to influence the blank screen in any way. Cheers, Tim
