The problem with modern tech is that it has reached such a level of sophistication that once you have a problem with it, it’s very difficult or nearly impossible to retrieve or recover.
The same is the case with modern LCD or LED monitors; a single bad LED or a backlight can ruin your whole monitor, and the cherry on the cake, you just can’t take your eyes off that particular black corner or spot.
If your monitor appears dark in one corner or at a particular spot, there is an issue with the backlighting.
If your monitor has old technology, you can replace the backlighting, which is usually a CCFL (Cold Cathode Fluorescent Lamp) based. This will solve your problem.
But if your monitor is LED-based with integrated backlighting, you will fail to salvage it. So you either need to buy the whole LED Panel or replace the monitor if you got a warranty.
Before diving deep into why my monitor appears darker in one corner, you must first understand how the modern monitor works. This will give you insight into the problem and better appreciate your concern’s magnitude.
Difference between LCD and LED Monitors
You will be amazed that LED (light emitting diode) is similar to LCD (liquid-crystal display) monitors with a few differences.
An LCD has a layer of liquid crystal between the polarized glass that aligns light from backlighting.
Older LCD monitors have backlighting that uses CCFL (Cold Cathode Fluorescent Lamp). Electric current passing through liquid crystals changes the alignment of crystals and thus produces different colors out of the backlighting.
In contrast, the newer generation of LCDs, called LED monitors, do not use this old-school CCFL. Instead, each LED (Light Emitting Diode) produces the light passed through polarised glasses to get color out of it.
The LED monitors are better than LCDs because they use less energy and last longer. Otherwise, both have variable pixel density and the same video quality.
Can I replace the backlighting of the LCD with integrated LED backlighting?
Now that you have understood the concept behind LCD monitors with CCFL backlighting and Integrated LEDs, it’s time to discuss the prevailing issue “Monitor Dark in one Corner.”
If your monitor is based on old CCFL-based backlighting, you have a fair chance of replacing it with a new one, and your problem of monitor dark in one corner will quickly be solved.
Note: Replacing CCFL backlighting is not an easy task. You will permanently damage the LCD screen if you are not an expert.
However, LED monitors do not offer this opportunity because each LED monitor contains thousands of these LEDs in less than a cm square. Therefore, if one side of the monitor has a dark corner, it means some of the LED has stopped working, and you can’t change these individual LEDs.
Therefore, you are practically left with no other option than to use a black corner, throw it away, or buy a new one.
Replacing a CCFL-based Backlight of a monitor/LCD
Removing CCFL backlighting is not an easy task, and you must be very cautious because a small mistake will damage your whole LCD screen.
Therefore, I do not recommend attempting it if you don’t have the expertise and courage. However, if you wish to proceed, follow these steps.
Step 1: Open the Monitor cover screws
Step 2: Separate the LCD panel from the body
Step 3: Remove sticky tape and foil from the back of the screen
Step 4: Carefully remove the tape from the backlight cables.
Step 5: Identity and then Carefully remove the circuit board. Be careful; it might be glued or screwed to the panel, and avoid flexing or bending the circuit board.
Step 6: Once you have successfully removed the circuit board, Place the LCD screen upright and remove the metal case using a credit card to unlatch it from all sides. The metal frame secures the LCD to the plastic frame we removed in step 1.
Step 7: Once you have removed the metal frame, you will see plastic layers, a CCFL lamp, and the reflector attached to the metal frame. Do not separate them, just pick the top layer and remove the metal cover from the backlight lamp (CCFL).
Step 8: Enroute the wires mounted to the plastic hook and remove the backlight and the reflector.
Step 9: Carefully unglue the reflector from the lamp and mark the places where wires go inside. It will help you reassemble it.
Step 10: Remove the rubber cap covering the wiring and unsolder them.
Step 11: Solder a new lamp to the wires and replace the back lamp inside the reflector.
Step 12: Check the lamp if it’s working. For this, carefully connect the wires to the LCD screen and turn the power on.
Before attempting to change the backlight, watch your every move and carefully place each item in its place step-wise so that you might not forget the steps.
Watch this video if you do not understand the steps and reread the blog;
Monitor Dark in one corner! Now, what’s next?
If you have a newer model of monitor that is basically an LED monitor, you can’t salvage the backlighting because they are embedded deep into the whole frame.
You have a few options, including buying a new one or claiming the warranty.
Most high-end monitors, especially LED monitors, have a one-year product warranty. So if you have a problem with your monitor within a year, they will either replace your LED monitor with a new one or repair it.
However, it is essential to know that before buying a monitor, you should have signed for the warranty package (they come with a premium price tag).
Additional Read!
