E6410 display - apparently wrong native resolution

Question

I have a Dell E6410 used primarily with Ubuntu 12.04, dual boot into Windows 7. Within the last few days (and without knowingly changing anything) the laptop display has stopped displaying correctly.  The image is still visible, but pale, with fine white horizontal lines, and text is distorted as if alternate rows of pixels were missing. Using F2 at boot shows the Natural Resolution as 1440 by 900, as does the Ubuntu nvidia-settings. However, I'm fairly sure that the display hardware is the 1280x800 version.  Certainly the behaviour is consistent with forcing 1440 horizontal lines onto a display that only has 1280. The appearance has the same problem when booted into Windows.  An external monitor works perfectly. Is it possible that the machine has got confused about its own resolution?  If so, how can I correct it?  If not, are there other diagnostics I should try?

dorienho · Accepted Answer

Update: Restarted Ubuntu and all resolutions are now visible. So I have one fully working machine!

Apologies to anyone following this thread in the hope of proper diagnosis and cure - "buy a new machine" and "hit it with a hammer" aren't really much use.

DELL-Ravi Ch · Answer

Hi dorienho,

Please reply us with the snapshot of the LCD screen so that we can check and assist you further.

Also, we will have to perform the ‘LCD BIST’ (Built in Self-test) on the computer. Please follow the steps mentioned below to run the “LCD BIST’.

Turn of the computer.
Press and hold down the ‘D’ key on the keyboard and press the Power button.
You will see different colors on the LCD screen. Please check if the issue reoccurs on the screen.

dorienho · Answer

Hi Ravi, thanks for replying!

The BIST test shows a cycle of five full-screen colours. Each screen is clean; i.e. the white screen is pure white, the yellow screen pure yellow, with no visible artefacts.

I have attached a screen snapshot showing the effect of the problem on text. The effect is visible even on the Dell splash screen at startup (although this goes too fast for me to get a picture) suggesting that it's a BIOS-level problem.

One hypothesis is that the EDID is corrupt. When I run get-edid | parse-edit I get the transcript below including the phrase "your EDID is probably invalid".

best wishes

Dorien

$ sudo get-edid | parse-edid
parse-edid: parse-edid version 2.0.0
get-edid: get-edid version 2.0.0

   Performing real mode VBE call
   Interrupt 0x10 ax=0x4f00 bx=0x0 cx=0x0
   Function supported
   Call successful

   VBE version 300
   VBE string at 0x11100 "NVIDIA"

VBE/DDC service about to be called
   Report DDC capabilities

   Performing real mode VBE call
   Interrupt 0x10 ax=0x4f15 bx=0x0 cx=0x0
   Function supported
   Call successful

   Monitor and video card combination does not support DDC1 transfers
   Monitor and video card combination supports DDC2 transfers
   0 seconds per 128 byte EDID block transfer
   Screen is not blanked during DDC transfer

Reading next EDID block

VBE/DDC service about to be called
   Read EDID

   Performing real mode VBE call
   Interrupt 0x10 ax=0x4f15 bx=0x1 cx=0x0
   Function supported
   Call failed

The EDID data should not be trusted as the VBE call failed
EDID claims 255 more blocks left
EDID blocks left is wrong.
Your EDID is probably invalid.
parse-edid: EDID checksum failed - data is corrupt. Continuing anyway.
parse-edid: first bytes don't match EDID version 1 header
parse-edid: do not trust output (if any).

   # EDID version 255 revision 255
Section "Monitor"
   Identifier "___:ffff"
   VendorName "___"
   ModelName "___:ffff"
   # DPMS capabilities: Active off:yes Suspend:yes Standby:yes

   Mode    "4095x4095"   # vfreq 9.770Hz, hfreq 80.018kHz
       DotClock   655.350000
       HTimings   4095 4350 4605 8190
       VTimings   4095 4158 4221 8190
       Flags   "Interlace" "+HSync" "+VSync"
   EndMode
   Mode    "4095x4095"   # vfreq 9.770Hz, hfreq 80.018kHz
       DotClock   655.350000
       HTimings   4095 4350 4605 8190
       VTimings   4095 4158 4221 8190
       Flags   "Interlace" "+HSync" "+VSync"
   EndMode
   Mode    "4095x4095"   # vfreq 9.770Hz, hfreq 80.018kHz
       DotClock   655.350000
       HTimings   4095 4350 4605 8190
       VTimings   4095 4158 4221 8190
       Flags   "Interlace" "+HSync" "+VSync"
   EndMode
   Mode    "4095x4095"   # vfreq 9.770Hz, hfreq 80.018kHz
       DotClock   655.350000
       HTimings   4095 4350 4605 8190
       VTimings   4095 4158 4221 8190
       Flags   "Interlace" "+HSync" "+VSync"
   EndMode
EndSection

DELL-Ravi Ch · Answer

Hi dorienho, It’s a problem with the LCD screen as the output on the external display is good. I would suggest you to private message me the system service tag so that I can check what can be done.

dorienho · Answer

Hi Ravi

I bought a new E6410 (they're cheap on eBay!) to see if it would help to resolve the problem. Swapping the hard drives between the two machines showed that:

- new hard drive in old machine still has poor screen display - so as you said, there is a problem with the display, but...

- old hard drive in new machine sets resolution to 800x600 in Ubuntu, and offers no other option, but works fine in Windows. It appears that, whatever happened when the display went bad, simultaneously confused something in Ubuntu. Meaning that we were dealing with both a hardware problem and a software problem.

I launched Ubuntu in Recovery Mode and reset the graphics defaults. It now displays at 1440x900 as the only option - which is perfectly acceptable, although not as good as having the full range of resolution choices. I will live with this in the hope that my next full OS upgrade will put it back to how it should be.

I may also take the old machine to a repairer... although not urgent now I have one that works.

best wishes

Locked Topics – Laptops General

Was this post helpful?