broken screen on toshiba laptop

1 ANSWERS

1. amomipais82
   

   Hi,
   Before you start working on any laptop or notebook computer, remove the battery. It's just too easy to accidentally power up a laptop when you're working on it, and that could easily spell disaster, even if you don't panic. The first part of the puzzle when you repair a laptop screen is to determine what the failure is. We aren't going to do that here, because there's actually nothing wrong with this Toshiba notebook, I'm just using it for example. The second step, once you know what you're trying to fix, is to find the screws to take apart the cover, which houses the LCD and inverter.
   Most Toshiba laptops use four screws to secure the plastic bezel, two at the top and two on the hinges.The top screws are hidden under some rubber bumpers, you really need to dig a screwdriver with an edge on it into the side to compress them enough to get them out. The screws below the LCD on the hinges are under rectangular paste ins that I needed a jewelers screwdriver to pry up.
      In all cases, the screws securing the plastic bezel around the laptop screen had some variety of loc-tite on the threads, and need a good deal of force to remove. It's critical to pick a screwdriver that matches well so you don't end up stripping the head.
   Once the screws are removed, we gain access to the LCD with it's backlight and inverter by prying open the plastic shell. It takes a sharp screwdriver to get it started unless you know exactly where to push in the snap-together injection molding. The funny thing about notebook computers is that they are actually incredibly tough, I've never broken one while working on it, even when I didn't have a clue how it was put together. Once you pop a couple of the snaps, you can sight down the crack and see where the others are, which makes it a lot easier.
   I don't have any particular order for doing this, so I started with removing the backlight from the top of the LCD. The backlight is secured to the LCD by two small screws that do require a jewelers Phillips to remove. Laptop LCD backlights are actually florescent bulbs, with CCFL (Cold Cathode Fluorescent Lamp) being a favored technology. The average life for a laptop backlight is on the order of 30,000 hours, or more than three years of 24 hour a day use. When the backlight in a laptop flickers or fails, it's more likely the inverter than the CCFL tube.
   Here we have the backlight removed from the top edge of the Toshiba screen (the LCD is actually manufactured by Sharp). It's a pretty simple design, one wire goes to each end of the tube, just like a regular florescent tube, and the inverter produces the high voltage, high frequency energy required to strike a plasma and keep it lit. This isn't terribly efficient, and newer laptop computers employ LCDs that don't require a backlight, which helps a great deal with battery life. The CCFL tube is tacked to the wire at each end with solder since it's not really intended to be disposable.The inverter that drives the backlight is a much more frequent cause of failure than the CCFL tube. The inverters are sold as modules, frequently remanufactured, for between $60 and $80 for most laptop models that employ them.
   It can be very frustrating to get a lemon version of a laptop that goes through inverters, particularly when the warranty expires. Removal and installation of the backlight inverter is actually pretty simple once the shell is open. Two screws hold this Toshiba inverter to the case, and there are also plastic guide pins for aligning it. Two plug in connectors, one for the LCD backlight (below, left) and one for the inverter control (below), complete the installation or removal. The final picture in the series is really just a reminder not to forget the LCD ground when you reinstall the LCD in the shell.
   Best of luck

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