Start a new topic

Sudden loss of screen brightness

I've suddenly had an issue where my Pi-Top will boot up an then Ill get the Pi-Top loading screen, but the screen will loose its brightness and go nearly completely black (to the point where I cant see my cursor to make changes). 

Any thoughts? 

Has anybody seen this issue before?

3 people have this problem

I too have this problem with the backlight and am a beginner with Pi-Tops although I have worked fine with an R Pi2 for a good while - but only know two or three terminal commands. I'm really stumped as I've got to run a Rasp Jam with six of these on 13th (a week on Monday) and I feel totally lacking in confidence with them now.  I usually manage to resolve issues with my own R Pi, but these Pi-Tops are very different, and then I write details of my progress up in my Geek Gran Wordpress blog but this time I'm completely stumped. Should I just put Raspbian Pixel SD cards in them?

You can certainly try to boot with a Raspbian Pixel SD card. This will work well unless the hub controller is stuck with brightness set to zero or backlight turned off. If that is the case, it is more difficult to recover.

1 person likes this

Hi Rene. I will try however I can't put a Pixel SD card in all six Pi_Tops but at least I may have one that works if as you say the brightness hasn't already been set low. Thanks.

Help! Is there any way I can shutdown safely when the screen has lost brightness? I can't see enough to do it properly.

I'm having the same issue.  Any solutions?


 I bought mine a few days ago, i disabled the xorg screen saver in pitop and this solved my problem, however they just released an update today with a new pitop dashboard and I LOVE IT! works smooth, it dims the screen properly now, and I like how it has the shortcuts to google services on the laucher! what can i say pitop just keeps getting better!

1 person likes this

Oh, that's good. Knew they would resolve the issue eventually!


Backlight can not be recovered, no matter how many times reboot.


When backlight could not be recovered, reboot pi-topOS. When pi-top splash screen appears, press Shift key (or arrow key; other key may work, too.) Backlight would be recovered.


You can not see the desktop. Use your keyboard. Press pi-top key to display applications menu. Press Up (arrow) key to select "Shutdown..." Press Enter key to display "Shutdown options" dialog box. Press Down (arrow) key to select Reboot. Press Enter key to execute Reboot procedure.

updated to polaris from the dashboard and then ran apt get upgrade on top of that: now my screen is randomly changing brightness settings. one moment will be fine, next it cycles to dark and will not return to the brightness I have se wthout a reboott.  or  it will go dard, then fgo full bright, then return to the brightness I have set. 

 I replaced polaris with pixel,  everything stays where i set it. 

I update to polaris and everything is fine. I go to get the other OS updates and the screen starts randomly changing brightness.

do I need to just do a fresh install of polaris?  I will try that in the morning.

anyone else having this issue? 

I think i have fixed theproblem  above.

the frty pin cable attaching the hub to the pi was loose on the hub side.  I reseated the cable and now all iseems okay.  with the cable loose, the pi was also showing a voltage issue durring boot up wit hte lighning bolt showin the in far uppre right cornerf the screen.  hope my issue helps someone else.

nope.  I didn't fix it.  it is still dimming the display at random times.  sometimes going full dark and stayying that way through a few reboots.  I have to pull the cable that connects the hup to the pi's gpio pins and then reboot  to get the brightness back.

I have no idea what is going on.

The update to the Polaris OS which came out a week or so ago seems to have sorted it, so that's probably the best way to proceed.


I am in the process of sorting it out now.  seems commenting out over_voltage =2 in config.txt had something to do with the undervoltage warning at boot.  I've re-added that back and put the pi's power settings in powersave mode (cpufrequtils).  I am still testing.  before I re-added the over voltage back in, videos would randomly darken and relighten the screen and my tv tuner in kodi would do that as well as sending a random shutown signal to the pi. 

I also reseated all cables just to be sure.  I will test kodi and my hdhomerun again today though and leave a message here after i do so.

just tested completely with a couple of DVDs in Kodi.  all issues in the message posted earlier seem to be fixed.  therewe re no random screen issues and n random shutdowns of the pi-top.  could have been the under voltage or a bad or loose cable was causing the issues. 

I have tracked down the issue.  will post in thread  ""pt-hub-controller Kodi bug""

Login or Signup to post a comment