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Backlight on laptop not working

Discussion in 'General Hardware' started by anonymous6366, Mar 23, 2013.

  1. anonymous6366

    anonymous6366

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    Anyone ever seen this happen? I got this toshiba x505-q870 from a friend because he dropped broke the screen and needed money. The backlight on the broken screen was working but then when I switched it out for the new one it stopped working (as in no matter which screen I plug in the backlights don't work). Any ideas why this is happening?
     
  2. Jetster

    Jetster

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    Were the wires go threw the hinge is very delicate. Try the other wires from the other laptop.
     
  3. anonymous6366

    anonymous6366

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    I looked at the wires very carefully because I know that is one area prone to damage but it looks like its good. There is only one laptop, two screens.
     
  4. Batou1986

    Batou1986

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    are you sure it was the screen that broke and not the inverter for the backlight
    [​IMG]
     
  5. kiddagoat

    kiddagoat

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    So you replaced the broken LCD panel with a new one and now there is not any power going to the screen?? If you put a flashlight up to the screen can you see a picture??

    Double check the inverter going to the LCD if there is one, pretty sure that Qosmio has one. Generally it only fits one way and the polarity of the inverter is marked with a blue dot or some other kind of marking.

    Also, sometimes though Toshiba doesn't usually do this, the panel you ordered as replacement might not need an inverter at all.

    And again double check the LVDS cable going to the LCD panel. It can be loose.
     
  6. anonymous6366

    anonymous6366

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    It does have an inverter and thats what I was starting to think was the problem. When I did some Googling that problem popped up a couple times.
    Once again, everything is plugged in correctly and I can barely see an image on the screen (because the screen is working just not the back light).
     
  7. Jetster

    Jetster

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    You can get a inverter and wiring on e bay.
     
  8. anonymous6366

    anonymous6366

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  9. kiddagoat

    kiddagoat

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    If you can on the bottom of the laptop give me the following information:

    Model Number: (Usually PSU, PSK or something other than the X505 number)

    I am an ASP for just about every manufacturer, I can get you the right part numbers for your particular laptop. Toshiba manuals are quite nice :) :) :)
     
  10. anonymous6366

    anonymous6366

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    its a x505-q870, but here is a pic with everything else
    [​IMG]
     
  11. Geofrancis

    Geofrancis

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    There is a few on eBay search x505 inverter.
     
  12. anonymous6366

    anonymous6366

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    I did, but the question still stands of which exact one I need. Maybe it doesn't even matter?
     
  13. Geofrancis

    Geofrancis

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    There should be a model number on the one you have so Just try eBay for every number on it.
     
  14. anonymous6366

    anonymous6366

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    yeah I did that before and none of them were my exact model number
     
  15. natr0n

    natr0n

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    I tried to fix a similar issue you describe for someone. I ordered new screen, inverters all that bs.

    In the end nothing worked. could only use with a external monitor.

    Letting you know as this will be a real hassle if you try it.
     
  16. anonymous6366

    anonymous6366

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    ^that best not be whats wrong...
     
  17. Geofrancis

    Geofrancis

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    It's either the inverter or ribbon cable it is extremely rare for the inverter power source on a motherboard to fail unless it's been shorted.



    Can you post the inverter numbers and a photo of both sides of the inverter?
     
  18. anonymous6366

    anonymous6366

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    Thats what I thought. Its just weird that it was working and as soon as I took the old screen off it failed.. anyway here is the inverter
    [​IMG]
     
  19. Jetster

    Jetster

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    Bad wires
     
  20. anonymous6366

    anonymous6366

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    the wires all look perfect, I guess its something to look into though. Is there a good way to test them?
     
  21. Jetster

    Jetster

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    I have been threw this a few times. Looks are deceiving. Just replace them if your going to replace the inverter.
     
  22. vawrvawerawe

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    Sounds like a faulty backlight. I would return and exchange for another while you still can.
     
  23. anonymous6366

    anonymous6366

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    If you read what I said in the first post neither of the screens backlights work so its not that
     
  24. kiddagoat

    kiddagoat

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    Sorry for the delay anonymous6366,

    Toshiba changed their ASP website and I needed to get access again.

    Here are your part numbers:

    A000048360 - Original Inverter that came with the unit

    These two part numbers are the other inverters that will work because usually the original is hard to find. A000048370 A000048380

    A000051860 - LVDS Cable from motherboard to panel

    This is another cable that will work. A000053600

    A000047700 - This is the original Panel number. Toshiba only lists one compatible panel for your laptop.
     
  25. anonymous6366

    anonymous6366

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