The image on the screen gets garbled when the laptop moved. To get the image back to normal you have to restart the laptop.
The image on the external monitor gets garbled too when the laptop moved.

Possible cause:

1. Bad connection between laptop video card and motherboard.
2. Bad video card.
3. Bad connection between laptop memory and motherboard.

Possible troubleshooting steps and repair solution:

When the video fails the same way on both the internal and external monitors, most likely the problem is related to the laptop video card.

1. If the laptop has a discrete video card, it could be connection related problem. Maybe the video card is not making good contact with the slot on the motherboard. Try reconnecting the video card. Apply electrical contact enhancer (I use DeoxIT® GOLD) on both the video card connector and motherboard connector. Test the laptop.

2. In most newer laptops the video card is integrated into the motherboard. In this case the video card cannot be removed and replaced. If the video card fails, you’ll have to replace the motherboard.

3. It’s not likely but possible that this problem is related to bad connection between the memory module and motherboard. Try reseating memory modules.

The laptop screen shows vertical dotted lines. The dots are red and moving up and down. The external monitor connected to the laptop either has garbled image or shows same dotted lines.

Possible cause:

1. Failed memory.
2. Failed video card.

Possible troubleshooting steps and repair solution:

If the problem appears on both the laptop screen and external monitor, it’s not related to the laptop LCD screen or video cable. Most likely the problem is related to the faulty memory module or video card.

Download Memtest86+ (google it) and test laptop memory. If the laptop has two memory modules installed, remove them one by one and test separately. If one of the memory modules fails test, move it to another slot and test again, just to confirm that it’s bad module, not the memory slot. Replace the failed memory module with a new one if needed.

If laptop memory passes test a few times, most likely there is a problem with the video card. In most laptops the video card is a part of the motherboard and cannot be removed and replaced separately. If the video card fails, you’ll have to replace the entire motherboard.

There are horizontal flashing lines running across the laptop screen. The laptop starts fine and you still can see the picture, but there are flashing lines running across a part of the image.

Possible cause:

1. Video card failure.
2. Bad connection between video cable and LCD screen.
3. Bad LCD screen.
4. Faulty video cable.

Possible troubleshooting steps and repair solution:

1. First of all, test the laptop video output on the external monitor. If you see same flashing lines running through the image on the external monitor, you have a problem with the video card. If flashing lines appear only on the laptop screen, the failure is not related to the video card.

2. Just in case, try re-seating the video cable connectors on the motherboard/video card and maybe the back of the LCD screen. It’ s not likely but possible that connection is loose and reconnecting the cable will fix the flashing lines.

3. If re-seating the cable connectors doesn’t help, most likely you have a faulty LCD screen. The LCD screen has to be replaced.

4. If replacing the screen doesn’t help, try replacing the video cable. It’s very unlikely that this problem is related to the video cable but there is a slight possibility of that.

The laptop screen shows wrong colors.

Possible cause:

1. LCD screen failure.
2. Video cable failure.
3. Corrupted video driver.
4. Video card failure.

Possible troubleshooting steps and repair solution:

1. Test the laptop with video on the external monitor. If wrong colors appear only on the laptop screen and video on the external monitor works fine, the problem could be related to the LCD screen or video cable.
- try reseating the video cable connection on the LCD screen.
- try reseating the video cable connection on the motherboard.
- replace the LCD screen.
- replace the video cable.

If colors on the screen appear to be inverted and the image looks like a negative, most likely it is the LCD screen failure.

2. If wrong colors appear on both internal and external screens, the problem could be related to the corrupted video driver or faulty video card.
- try reinstalling the video driver.
- try reinstalling the operating system from scratch and installing the video driver.
- if first two steps do not help, most likely you have a failed video card.

Most newer laptops have video card integrated into the motherboard. The integrated video card cannot be removed and replaced separately from the motherboard. When integrated video card fails, it’s necessary to replace the whole motherboard.

When you start the laptop, there are lines running though the manufacturer’s logo. Windows will not load. Same lines running through the logo appear on the external monitor.

Possible cause:

Video card failure.

Possible troubleshooting steps and repair solution:

When you have lines running through the laptop logo on both internal and external screens, most likely the laptop has a failed video card.

If the video card is a discrete module, you can try reseating the card. Unplug it from the motherboard and plug back in. It’s possible this failure occurs because of bad connection between the video card and motherboard. If reconnecting the card doesn’t help, you’ll have to replace the video card.

In most laptops the video card is integrated into the motherboard and cannot be removed and replaced separately. If the video card fails, you’ll have to replace the whole motherboard.

Some regions on the laptop screen are little pinkish. Same pinkish effect appear on the external monitor connected to the laptop.

Possible cause:

Video card failure.

Possible troubleshooting steps and repair solution:

When the same video defect appears on both the internal LCD screen and external monitor, most likely this is related to the video card failure.

In most laptops the video card is integrated into the motherboard. If the video card fails, it’s necessary to replace the whole motherboard.

If the video card is a discrete module, you can replace just the video card without replacing the motherboard.

The laptop has garbled image on internal screen and external monitor. In some cases the garbled image appears as soon as the laptop is turned on. In other cases the video works fine in safe mode but not in normal mode. But the image always fails on both the internal screen and external monitor.
Reinstalling the video driver doesn’t fix the problem.

Possible cause:

1. Shared memory failure.
2. Video card failure.

Possible troubleshooting steps and repair solution:

1. If the laptop uses shared video memory (part of the main memory is used for the video purposes), it’s possible that you have a faulty RAM stick.
- Test your laptop memory with Memtest86+ and if the test fails, replace the RAM module.
- Test your laptop with a known good RAM stick and find out if it fixes the problem.

2. In new memory doesn’t fix your problem, most likely you have a faulty video card.
In most laptops the video card is integrated into the motherboard. When the video card fails, it’s necessary to replace the whole motherboard.
In some laptops, the video card is a discrete module and could be replaced separately from the motherboard.

Laptop displays some random characters on the screen with initial manufacturer’s logo. Random characters are scattered all over the screen and appear as soon as you start the laptop.
You can distinguish vertical rows or random characters.

Possible cause:

1. Shared video memory failure.
2. Video card failure.
3. LCD screen failure.

Possible troubleshooting steps and repair solution:

1. If your laptop has shared video memory (part of the main memory is used for video purposes), try replacing the memory module with a known good one and test the laptop.
If you have two memory modules installed, try removing them one by one and test the laptop with each memory module separately. This way you can isolate the faulty memory module.

2. Test your laptop with an external monitor. If random characters appear on both internal and external screen, most likely your problem is related to the video card.
In laptops with discrete video card you can replace just the video card.
In laptops with integrated video card (it’s built into the motherboard) you’ll have to replace the whole motherboard.

3. If random characters appear only on the laptop LCD scree but external video works normal, most likely it’s related to the LCD screen. You’ll have to replace the screen.