Blank laptop screen

[R Robinson]

Since the upgrade to 3.13.0-85-generic, my laptop screen is blank from when I would normally see the 'Kubuntu' logo at boot time onwards. An external monitor still works OK. I can see that the laptop backlight is on but the display is black.

If I select 3.13.0-83-generic from the grub menu, everything works OK.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-85-generic 3.13.0-85.129
ProcVersionSignature: Ubuntu 3.13.0-85.129-generic 3.13.11-ckt36
Uname: Linux 3.13.0-85-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.19
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: tom 2370 F.... pulseaudio
 /dev/snd/controlC0: tom 2370 F.... pulseaudio
CurrentDesktop: KDE
Date: Sat Apr 23 23:16:23 2016
HibernationDevice: RESUME=UUID=ace2d751-8189-4d15-af74-400039ff0c8f
InstallationDate: Installed on 2014-06-07 (686 days ago)
InstallationMedia: Kubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.1)
MachineType: SAMSUNG ELECTRONICS CO., LTD. 900X3G
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-85-generic.efi.signed root=UUID=cc0b4c31-1aa1-4c9d-88af-97ca40f80655 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-85-generic N/A
 linux-backports-modules-3.13.0-85-generic N/A
 linux-firmware 1.127.22
SourcePackage: linux
StagingDrivers: rts5139
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/31/2014
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P07ADU.029.141031.PS
dmi.board.asset.tag: No Asset Tag
dmi.board.name: NP900X3G-K02FR
dmi.board.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.board.version: SAMSUNG_SW_REVISION_1234567890ABCD
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 9
dmi.chassis.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP07ADU.029.141031.PS:bd10/31/2014:svnSAMSUNGELECTRONICSCO.,LTD.:pn900X3G:pvrP07ADU:rvnSAMSUNGELECTRONICSCO.,LTD.:rnNP900X3G-K02FR:rvrSAMSUNG_SW_REVISION_1234567890ABCD:cvnSAMSUNGELECTRONICSCO.,LTD.:ct9:cvrN/A:
dmi.product.name: 900X3G
dmi.product.version: P07ADU
dmi.sys.vendor: SAMSUNG ELECTRONICS CO., LTD.

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.6 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.6-rc6-wily/

[penalvch (penalvch)]

R Robinson, the next step is to fully reverse commit bisect from kernel 3.13 to 4.6-rc6 in order to identify the last bad commit, followed immediately by the first good one. Once this good commit has been identified, it may be reviewed for backporting. Could you please do this following https://wiki.ubuntu.com/Kernel/KernelBisection#How_do_I_reverse_bisect_the_upstream_kernel.3F ?

Please note, finding adjacent kernel versions is not fully commit bisecting.

After the fix commit (not kernel version) has been identified, then please mark this report Status Confirmed.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]