How to Decide if your Laptop Screen is Faulty or is Failing

It is often difficult to decide if a laptop display problem is caused by a faulty screen or other laptop component. Sometimes it is obvious if the screen is cracked but more often the fault is more subtle where lines or blocks are seen on the screen. Before proceeding it is often useful to plug an external monitor into the VAG socket of the laptop (if it has one) to confirm that a good display can be produced. If the external monitor produces the same fault that is seen on the laptop screen then the fault probably does not lie with the laptop screen.

You may notice any of the following that may be caused by a faulty or failing display in your laptop:-

1. The screen may have a visible crack or what looks like a ‘spider's web' or you see what looks like ‘ink' leaking from the screen. When you turn on the laptop you may even see a partial picture up to the cracked area. Any of these observations indicate that the screen has been cracked. A broken screen cannot be repaired it should be replaced.

2. When you turn on the laptop you may see either a completely black or completely white screen. This fault may be caused by a faulty screen or more likely the screen data cable has become detached from either the screen or motherboard or it may even be damaged. Sometimes the repair would be as simple as removing and reinserting the cable at both the motherboard and screen ends. If the fault is still present then the screen may be faulty and should be changed to confirm this.

3. The laptop may apparently power up correctly except the display on the screen is very dim. This would indicate that the screen backlight is not coming on. Many laptop screens have a very thin long glass tube that illuminates the display. Sometimes the tube fails or breaks; however, cable faults, motherboard faults etc can stop this tube from lighting. If the tube has failed it can be replaced by a laptop repair expert; this is not a DIY job as the tube can easily shatter.

4. The laptop may power up correctly with a perfect display then randomly the screen may flicker. Either the entire screen or just a small area may flicker. This fault is almost always cased by a failing screen and can only be diagnoses by changing the screen.

5. The laptop may power up correctly except a single or multiple thin lines or colour bars are seen on the display. You may notice that if the screen or lid is moved very slightly the line or lines either come and go or change in colour. This usually indicates that the screen has been damaged and needs to be replaced.

6. The picture may appear ‘washed out' or blurred. This usually indicates a faulty screen although a faulty graphics chip can give similar symptoms. The screen should be changed to confirm this.

Screen removal and replacement should only be attempted by a laptop repair expert as it is very easily damaged. Be especially careful when reinserting the data cable into the screen as you can very easily damage it by a wrong insertion. Try not to handle the screen in the area where the electronics are, there is usually a warning printed by the manufacturer.


Graham has had many years experience repairing defective laptops, netbooks, notebooks and repair USB drives; specialising in fixing motherboards at component level for Laptop repair is always difficult but is very rewarding when an obscure fault is located and fixed.

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