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Galaxy Nexus and display backlight

Added by Drtan Samos over 3 years ago

Hi!

Like on any other model there is a time which when elapsed the display goes to the sleep mode. I have noticed that when this occurs on my Galaxy Nexus and I bring it to a dark room the display either flashes with backlight or the backlight is continuously on. I think this is the case also when I keep the device in well lit room. I don't know whether it is a normal situation. I suspect not, as the battery charge level goes down quite fast. I am running Replicant 4.2. I've seen this problem running previous versions of Replicant. Is this problem known to other Galaxy Nexus users? Is it Replicant problem or a hardware problem? What can I do? I tried to adjust display settings, but neither defaults nor some adjustments to display settings fix the problem.

Thank you for your interest towards this issue.


Replies (8)

RE: Galaxy Nexus and display backlight - Added by Paul Kocialkowski over 3 years ago

That looks like a hardware issue, maybe other users could confirm. Backlight should be handled the same way as in CyanogenMod, so you could check that it's not Replicant specific by installing CyanogenMod and checking whether it happens or not there.

RE: Galaxy Nexus and display backlight - Added by Drtan Samos over 3 years ago

It appears that it is not a hardware issue. I have just installed CyanogenMod 10.2 on the device and the problem is gone. I can also be reasonably sure that previous CyanogenMod releases didn't have the problem either. I used CyanogenMod before I knew Replicant. How can I trace the cause of the problem? Is there a way I can provide more details of the problem?

RE: Galaxy Nexus and display backlight - Added by Eric Fontaine over 3 years ago

I can confirm that this backlight is draining my galaxy nexus battery when in sleep mode. I have been using cyanogenmod 10.2 and 11 till last week, and was always getting a full day's use on charge, and now that I installed replicant 4.2, I'm getting only ~6 hours, so I know this is not a problem with my hardware. When I'm in a dark room, I also notice a faint backlight when in sleep mode, so that is the obvious culprit. (Note: as far as I can remember, I do not remember having this issue when I was using the previous version of replicant 4.0005 last year)

RE: Galaxy Nexus and display backlight - Added by Paul Kocialkowski over 3 years ago

I got a Galaxy Nexus recently and saw the issue. I know what's going wrong and I'll try to fix it for the next 4.2 release. Mostly a missing FBIOBLANK ioctl.

RE: Galaxy Nexus and display backlight - Added by Drtan Samos over 3 years ago

Does the release 4.2.0002 fix the issue?

RE: Galaxy Nexus and display backlight - Added by Paul Kocialkowski over 3 years ago

Yes it does! I spent some time figuring out the problem and now it's resolved. I have used the device for one week and the battery consumption was normal.

RE: Galaxy Nexus and display backlight - Added by Drtan Samos over 3 years ago

That's amazing news. Replicant is back on my phone. Thanks a lot, Paul!

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