What Makes LCD Screens Go Dark, and Can I Fix It?

Discussion in 'Automotive Electronics' started by Zero Potential, Aug 17, 2016.

  1. Zero Potential

    Thread Starter Member

    Mar 25, 2015
    My elderly father has a 2002 Infiniti Q45. It has a video screen that controls the AC and radio. The screen has gone almost completely dark. I'm having a hard time locating the part.

    My question: when an LCD screen craps out like this, is it usually a catastrophic failure, requiring total replacement, or is there some kind of backlight component I could hope to remove and replace? I know I can't get a conclusive answer from people who haven't seen the part, but I am hoping there is an answer which is usually applicable to LED screens made at this time.

    The screen still shows lettering and pictures. It's just very dark.

    Sorry; I accidentally wrote "LED" in the title, and now I can't fix it. I assume the screen is LCD, but I don't know for sure.
  2. bertus


    Apr 5, 2008

    I have changed the LED to LCD in the title for you.

    When there has been pressure on the LCD, it can go black.
    Unfortunately, there is no way to restore it.

  3. Zero Potential

    Thread Starter Member

    Mar 25, 2015
    Thanks for the help. Now I'm thinking about it, and I think I should have called it an LCD in the first place. It's a color screen, just like a 2002-era laptop.
  4. wayneh


    Sep 9, 2010
    Laptops and many LCD displays have a fluorescent backlight. They are powered by an inverter and are known to go bad, and sometimes a dark laptop can be repaired with a new inverter or light. There's a chance this is your problem.

    Sadly, the chance of using this knowledge to actually make a repair is low. I suspect repair parts may be very difficult to find, even if you can get this thing apart and pull out the fluorescent backlighting panel without harming anything.
  5. jpanhalt


    Jan 18, 2008
    From personal experience, as well as lots of stuff on the internet, when that HV supply goes out, it may be just a matter of replacing the electrolytic capacitors. I did that to a SyncMaster 213T LCD monitor several years, and it still works perfectly -- I am using it right now.

    Did the screen turn black in parts that spread or did it just turn black all at once? The latter is more likely the capacitors. The former is more likely physical damage.

  6. Zero Potential

    Thread Starter Member

    Mar 25, 2015
    The whole thing is black, but it's slightly brighter at the edges. Maybe I need to fix the caps.
  7. thisguy1

    New Member

    Aug 18, 2016
    Shine a flash light on it, If you see something then its your inverter board
  8. GopherT

    AAC Fanatic!

    Nov 23, 2012
    The slightly brighter at the edges is a give-away that it is fluorescent back-light and the tubes or the power supply are bad.
    - Most likely the power that supply (inverter) for those tubes.
    - most likely the electrolytic caps on the inverter.

    I would pull it out and take a look. Then post some photos and ask for more advice. Also, let us know where you are located. There may be a long-time member here living a few miles away who is willing to help.
  9. ian field

    AAC Fanatic!

    Oct 27, 2012
    Years ago I had a rather nice Sharp calculator - it was long and thin, so putting it in my back pocket probably wasn't such a good idea!

    A few years ago I noticed dark clouds gathering along the top edge of the LCD.

    The consensus of opinion seems to be that the panel has been flexed and the edge seal is now allowing the ingress of moisture.
  10. bwilliams60

    Well-Known Member

    Nov 18, 2012
  11. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    Sounds like its the backlight at fault, or it maybe illuminated by bulbs.

    Any pictures of it?