Laptop LCD Screen Problems and How to Diagnose Them

There are a number of factors that come into play in diagnosing a laptop display problem:

Does the Screen have a displayed Image?

If the laptop has no image at all it can be video card or LCD cable or the LCD panel. About the only non-invasive test you can try is to plug an external monitor into the laptop. This will determine if the problem is motherboard/graphics card or lcd cable/lcd screen. If you have an image on the external monitor then its likely to be lcd/cable/lcd screen.

Is the Displayed Image Faint?

A dim screen can be caused by three things;

1/ The LCD inverter which runs the LCD backlighting

2/ The CCFL backlighting fluro tube in the LCD panel

3/ The motherboard supplying signal & voltage to the inverter.

Most commonly (say 80% of the time) it's the inverter, 10% it's the ccfl tube in the LCD panel, and 10% it's the motherboard or the LCD cable from the motherboard to the LCD screen. We have hundreds of laptop inverters in stock and can supply inverters for models that the manufacturer do not sell separately (eg HP or Dell) and where they want you to purchase a whole new lid assembly. In the rare cases where its not the inverter, if it's the LCD panel or the motherboard costs would higher and we'd quote you.

Is the Image fragmented or broken with random geometric shapes?

If the image is covered by a pattern of random squares or rectangles it can indicate a faulty graphics card or faulty graphics card memory. Plug an external monitor into the laptop. This will determine if the problem is motherboard/graphics card or lcd cable/lcd screen. If you have a good image on the external monitor then its likely to be lcd cable/lcd screen. If the image is the same on the laptop and the external monitor it is likely to be the motherboard or video card.

Is The Graphics Card On-Board or Separate?

To determine if the model of laptop has an onboard graphics function or separate graphics card would require a bit of Google research. Typical motherboard cots can be $500-$1000, Typical graphics card costs from $150 to $250.

Are There Lines on the display from top to bottom or side to side?

Lines on the screen indicate a faulty LCD panel. 17" Toshiba models are notorious for this.

The screen is broken, cracked, or delaminating. Can this be fixed ?

Again this indicated the screen needs replacing. It is not possible to fix a cracked screen.

A proper Image comes and goes when the Laptop lid is Wiggled?

If the laptop alternates between a faulty display image and a good image when you wiggle the lid, this can indicate either a faulty LCD cable or a poor cable connection. On disassembly the LCD cable can be inspected for rub wear and other problems. This is not a huge problem to fix.