Toughbook CF-30 CCFL Backlight Failure

Discussion in 'Panasonic' started by Mark Wickens, Sep 20, 2016.

  1. Mark Wickens

    Mark Wickens Notebook Enthusiast

    Reputations:
    5
    Messages:
    32
    Likes Received:
    14
    Trophy Points:
    16
    Hi all. Hope you are all well. A few days ago I noticed a flickering of the backlight on my CF-30 Mk3 which progressively got worse until today when the backlight failed. If I turn the laptop off and on it will run for a bit but then drops out completely again.

    I'm presuming this is the inverter that is on the blink - given that it is a failure from both sides of the display. The CCFL tubes are quite yellowed and if the numbers are correct the laptop has run up around 30,000 hours - although it is in excellent cosmetic condition.

    So the question is - LED conversion or replace the CCFL's and inverter? I'm presuming the inverter is a Toughbook specific part and a generic unit wouldn't fit (although I am also presuming that the CCFLs can be bought from a 3rd party supplier)?

    I *can sometimes* be fairly handy when it comes to electronics but TBH the more difficult the job the more I'm likely to mess it up. Although I have been known to swap positive and negative on the simplest of circuits!

    I'd like to do the LED conversion, but need some comforting words before I take a screwdriver to my lovely CF-30!

    Thanks for the help - and all the previous trail blazing that makes this even a possibility.
    I'm considering the following LED backlights: http://www.ebay.co.uk/itm/111748838166
     
  2. Shawn

    Shawn Crackpot Search Ninja and Options Whore

    Reputations:
    1,524
    Messages:
    8,042
    Likes Received:
    1,845
    Trophy Points:
    331
  3. safn1949

    safn1949 I'm sure I'm on the wrong planet

    Reputations:
    135
    Messages:
    1,083
    Likes Received:
    306
    Trophy Points:
    101
    The LCD and inverter are easy to replace,if you don't feel comfortable doing a LED retrofit.
     
  4. Mark Wickens

    Mark Wickens Notebook Enthusiast

    Reputations:
    5
    Messages:
    32
    Likes Received:
    14
    Trophy Points:
    16
    Thanks for the help. I've reviewed the three posts about LED replacement again. I have contacted the seller of the LED strips to determine whether they are suitable. I'd like to convert to LED's, so if I can do it at a reasonable cost I'll give it a go.

    Cheers, Mark.
     
  5. Mark Wickens

    Mark Wickens Notebook Enthusiast

    Reputations:
    5
    Messages:
    32
    Likes Received:
    14
    Trophy Points:
    16
    I had a response from the seller - with a question. I wonder if anyone can confirm this?

    So this panel uses two CCFLs.
    First check if original inverter input has the same regulation as usual inverters
    5v on start up and 0 till 3,3v regulation

    Thanks, Mark
     
  6. Shawn

    Shawn Crackpot Search Ninja and Options Whore

    Reputations:
    1,524
    Messages:
    8,042
    Likes Received:
    1,845
    Trophy Points:
    331
    Schematic lists it as Vc5, so I will say 5v.
     
  7. CWB32

    CWB32 Need parts for my flying saucer.

    Reputations:
    179
    Messages:
    1,565
    Likes Received:
    412
    Trophy Points:
    101
    while i like the idea of leds over ccfls the realities are another story .
    having recently had a go at retrofitting a led strip into an exceedingly dim '52 (they were like that brand-new) , there are a couple of considerations ...
    a major problem i ran into was the "stage footlight" effect ... this comes from the fact that the diffusion characteristics were designed for a lineal light source , not the "spot sources" that a led strip has .
    this effect is a deal killer for me ... with some other issues on the side (such as the way that the pwm is done with cmos driver/buffer) .
    if it were me , i would replace the ccfls and an electrolytic cap on the inverter board and call it a day .

    one could always replace the whole lid assembly but unless the '30 has been sitting in a closet for many years , the ccfls in these machines are going to be "tired" .
    i do not know if it is possible to retrofit a whole lid assembly from a '31 onto a '30 base , but if all things jibed , this would be the way to go .
    the voltage supply for the inverter and the "direction" of the pwm signal are the first two major concerns (although , one could make an inverter for the pwm signal) .
     
  8. Mark Wickens

    Mark Wickens Notebook Enthusiast

    Reputations:
    5
    Messages:
    32
    Likes Received:
    14
    Trophy Points:
    16
    Thanks for the info CWB32. Regardless of what I decide, is there an obvious fault that causes these symptoms? I'd be quite happy to replace an electrolytic or two on the inverter board to get the machine up and running again till I decide what I want to do as a permanent fix. If I went down replacing the CCFLs - are they a standard part I can get from a 3rd party supplier? Is it simply a case of getting tubes the correct length?

    Cheers, Mark.
     
  9. Mark Wickens

    Mark Wickens Notebook Enthusiast

    Reputations:
    5
    Messages:
    32
    Likes Received:
    14
    Trophy Points:
    16
  10. Shawn

    Shawn Crackpot Search Ninja and Options Whore

    Reputations:
    1,524
    Messages:
    8,042
    Likes Received:
    1,845
    Trophy Points:
    331
    They appear to be ok.
    You may have to do some minor custom work with the rubber ends since the CF30 uses 2 tubes side by side.
     
Loading...

Share This Page