Dim Screen on your Laptop? Blame the backlight!
Aside from the usual broken screen, another common laptop display failure is when text and graphics are still visible on the display under bright conditions, but appear very dark because there’s no lighting from behind. This fault is related to the backlight (the white light source that lights up the screen); either the backlight itself is faulty or the circuitry supporting it has failed.
See the split “before” and “after” picture if you’re not sure what this looks like.
(Now click here if you want to skip the detail and just get your dim laptop fixed!)
Inverter Failure and Repair
The older CCFL (cold-cathode fluorescent lamp) backlights require a special circuit called an “inverter” to generate the high voltages they need. If the inverter has stopped working for whatever reason, the backlight won’t come on, resulting in a “dull screen” unlit display.
Fortunately, inverters are generally cheaper to replace than the entire screen, and almost certainly far cheaper than buying a replacement notebook computer. If you think that your laptop’s inverter has failed- or even if you’re not sure what the problem is- bring it to us.
Inverter failures are mainly found in CCFL-backlit displays. LCD screens using newer-style LED backlights* usually don’t require such high voltages, and don’t require an inverter. However, the backlight may still fail for other reasons.
* Confusingly, most so-called “LED monitors” are still LCD monitors(!). They still use LCD layers- with a colour filter- to generate the pixels. The difference is that the white backlight uses LEDs instead of the CCFL tubes used in older models. (Of course, despite the very similar names, LCDs (liquid crystal displays) and LEDs (light-emitting diodes) should not be confused!)
Other Causes of Dull Notebook Screens
Apart from faulty inverters, a dim laptop screens may also be caused by the backlight itself being broken. Faults with case buttons or sensors can also cause the computer to think the case is closed when it isn’t, and turn off the display. (Though in such cases, the display is more likely to disappear entirely rather than simply going dim.
I Don’t Care About That… Just Fix My Laptop!
If your brain went numb reading the article above- don’t worry. Whatever the cause of your laptop’s dim screen, bring it to Disc Depot, and we’ll let you know how easy it’ll be to repair. You can find us in Dundee city centre, just off the Nethergate- or why not telephone or email us? Our details are at the bottom of the page.
