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Last week, my laptop display unexpectedly decided to go haywire while it was switching graphic cards (going from ATI Radeon to Intel GMA). Now the image is displayed "right-to-left" instead of the normal "left-to-right". Some of you might already be thinking that it's just the screen inversion/rotation of the display driver, but NO, it's definitely a hardware problem as this behavior starts as soon as the computer boots with the BIOS screen and I have tried every setting I could think of.

Conversely, the display is fine with an external screen, both on VGA and HDMI outputs.

I have included two photos so that you can understand what the problem is about:

Laptop display: image is inverted + every other vertical line is swapped

enter image description here

External screen: image is normal

enter image description here

So now, since the laptop is out of warranty (but just 1.4yo and always handled with care) and I don't have the money to buy a new one (+ I think it would be a waste just for a display problem), I was thinking of simply getting a replacement screen (no problem installing that).

However, since I have not figured out exactly the root cause of the failure/current behavior, I also can't rule out that the problem might lie somewhere else. Thus I would like to know your view on the matter:

  • Has anyone ever had the same problem?
  • Do you think it's safe to assume that it's only a display problem since the VGA and HDMI outputs work fine?

Information about the computer

More informations about the computer if that can be of any help:

  • Brand: Acer
  • Model: TimelineX 4820TG (4820TG-334G32Mnks to be exact)
  • Graphic card: ATI Radeon Mobility HD5470 / Intel GMA (switchable graphics)
  • Year of purchase: October 2010 (labels indicate if was manufactured May 2010)

Link to the Service Manual.

New information about screen (+datasheet)

I have tried to disassemble the screen (hoping it would be something easily resolved like a loose cable connection). This attempt was unsuccessful for solving my problem, but allowed me to note down the exact screen model:

  • Manufacturer: AU Optronics (AUO)
  • Model: B140XW03 V.0
  • Version: H/W:0A F/W:1

And Google helped me find the relevant datasheet. However my limited knowledge on the subject did not allow me to get much out of this document for solving the issue: I hope others can find it more helpful...

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I'm sorry I could not include the image directly in the question, but apparently I'm not allowed to do that as a (almost) new user... –  Federico Feb 14 '12 at 21:19
    
Fixed the photos for you (: –  BloodPhilia Feb 14 '12 at 21:21
    
Can you include the specific make and model of your laptop? And perhaps year purchased? It would make it a lot easier to research your particular hardware. –  Ben Richards Feb 14 '12 at 21:27
    
Have you tried mirroring the screen via ATI settings? –  soandos Feb 14 '12 at 21:30
    
Could you clarify please? You state: > ...decided to go haywire while it was switching graphic cards (going > from ATI Radeon to Intel GMA). Are you saying you physically changed the graphic card (hardware) in the laptop? Does switching back resolve the problem? –  JonnyBoats Feb 14 '12 at 21:41
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2 Answers

This is a particularly intriguing problem.

My guess, initially, is that the display controller specifically for the internal laptop display somehow has messed up the way it clocks data out to the actual physical display. My guess is that it probably handles requests a vertical column at a time, and perhaps the timing got messed up. I would think it's a hardware failure.

However, I cannot be certain of this with the limited information I have right now. I'll see if I can research this some more and come back with some more details...

EDIT

I did a lot of googling (well, Bing-ing :P) and it led me to start looking at the tech specs for the display panel itself. What's particularly interesting, I think, is on page 17 and 18 of this document, which is the tech sheet for your particular panel: http://www.displayalliance.com/storage/B140XW03_V_0.pdf

I learned while looking up this information that some panels do have a specific pin on the connector that can specify R/L scan direction. Yours does not, but it does say that horizontal sync is synchronized to RxCLKIN, which is on pins 17 and 18. I'm not very familiar with LVDS interfaces and how this protocol operates, so my attempts to gleam more detail out of what's there won't yield much. However, my guess is that you may have a damaged pin. I'd start with the RxCLKIN pins and see if there's anything that isn't connecting properly, if you want to try and fix it. If you're not comfortable with doing so, I'd say just buy a replacement and hope that it works.

If it doesn't, then the laptop may be messing up the signals going into the display, and if that's the case, you may have to look into replacing the motherboard of the laptop. Or just buy a new laptop. :P Either way, it's up to you at that point.

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Even if there is a hardware failure, it might be possible to correct with software –  soandos Feb 14 '12 at 21:32
1  
@soandos That is true, depending on the type of failure. Hence my desire to research it further. :) However, since he said it occurs even during POST, it must have a hardware cause. –  Ben Richards Feb 14 '12 at 21:35
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I don't know if this could be of any relevance, but I said the problem occurs "as soon as the computer boots", thus with the ACER logo and inside the BIOS config menu if I press F2, but I have silent boot enabled: thus I never see the actual POST running... –  Federico Feb 14 '12 at 22:10
3  
@Federico For all intents and purposes it's not really relevent, though thanks for clarifying. The point is that it occurs before the OS loads, and so it's not particularly a software issue (on that level). –  Ben Richards Feb 14 '12 at 22:18
    
@sidran32 If it can be one any help, I have edited the question to add the exact screen model and a link to the datasheet. Maybe that can shed some light on the timings that you mentioned. –  Federico Feb 14 '12 at 23:14
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up vote 1 down vote accepted

For future reference, I ended up replacing the LCD panel. The computer/display works fine now, as it used to.

Maybe one day I'll have more time/knowledge/equipment to investigate what happened exactly to the faulty LCD panel. Meanwhile, I hope this question can help others encountering the same issue...

Many thanks to all who helped and shared their knowledge!!!

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