When you push on the power button, the power light on the laptop turns on but the screen shows no image. The laptop screen remains black and blank. Video on the external monitor also not working even though it used to work fine before.

Possible cause:

1. Memory failure.
2. Video card failure.
3. Motherboard failure.

Possible troubleshooting steps and repair solution:

1. Try reconnecting memory modules, maybe one of them is not making good contact with the memory slot.
Try removing memory modules one by one. Maybe one of the memory modules is bad. The laptop might start properly when the faulty memory module is removed.

If you have only one memory module, try moving it to another slot. Maybe the slot itself is bad.

Try replacing memory module with another known good module.

2. If you have a discrete video card, which is not common, there could be a problem with the video card.

First, try reconnecting the video card to the motherboard. Maybe connection between the video card and motherboard is bad.
If reconnecting the video card doesn’t help, try replacing it.

3. In most newer laptops the video card integrated into the motherboard. If the video card fails, you’ll have to replace the motherboard.

If playing with memory modules (as explained in step 1) didn’t help, most likely there is a problem with the motherboard and it has to be replaced.

The laptop screen flickers on and off.

Possible cause:

1. Screen inverter failure.
2. Backlight lamp failure.
3. Bad video cable.
4. Video card failure.

Possible troubleshooting steps and repair solution:

First of all, take a closer look at the screen when it flickers. Is it losing just the backlight and the image stays on the screen or it loses both the backlight and image?

1. Laptop loses backlight and image when screen flickers.
- test your laptop with video on an external monitor. If video flickers on both the laptop screen and external monitor, there is a problem with the video card.
- if you see flickering only on the laptop screen, it’s either bad video cable or faulty LCD screen. Try reconnecting the video cable. Try replacing the video cable. Try replacing the LCD screen.

2. Laptop loses only backlight when screen flickers. The image is always on the screen.
- bad screen inverter board. Replace the inverter board.
- bad backlight lamp inside the LCD screen. Replace the LCD screen.

The laptop has to video on the external monitor connected to the VGA port. The laptop screen works fine.

Possible cause:

1. External monitor turned off.
2. Wrong settings.
3. Bad VGA cable or bad connection.
4. Bad VGA port on laptop.

Possible troubleshooting steps and repair solution:

1. Make sure the external monitor is turned on.

2. The laptop is set to output video only on the internal screen. On most laptops you can switch video output between internal and external screens using a keyboard shortcut. You hold down the Fn key and at the same time press on of the F keys. This shortcut is different for different brands.

For Toshiba laptops use: Fn+F5
For HP laptops use: Fn+F5
For IBM/Lenovo laptops use: Fn+F7
For Dell laptops use :Fn+F8

Some other brands may have different shortcuts.

Connect the external monitor to the laptop, make sure the monitor is turned on and use one of the above mentioned shortcuts to switch video from internal to external mode or set the laptop to display on both screens. The video output depends on how many times you press on the F key.

In some brands you can enable or disable output on the external screen in the BIOS settings. Enter the BIOS menu and search for the video output settings in there.

3. Try reconnecting the VGA cable connecting the laptop and monitor. The cable could be defective. Try replacing the cable.

4. There is a slight chance that the VGA port on your laptop is defective. In this case you’ll have to replace the VGA board or motherboard, it depends on the model of your laptop.

The laptop starts with a blank screen. The laptop stays on but no image appears on the screen even after a few minutes.

Possible cause:

1. Backlight failure.
2. Memory failure.
3. Motherboard failure.

Possible troubleshooting steps and repair solution:

First of all, take a closer look at the screen and make sure that the screen is really blank. Look under a bright light. If you can see a very faint image, most likely it’s either bad inverter or faulty backlight lamp. Try replacing the inverter board first and if it doesn’t help, replace the LCD screen.

In a case of the backlight failure, you still should be able to use the laptop with an external monitor attached to the VGA port.

If the screen is completely blank and has no image at all, check the memory modules. It’s possible that one of the modules has failed. Try reconnecting memory modules. If you have two modules installed, try removing them one by one. Test the laptop with each modules separately. Try replacing memory with another known good stick.

If manipulations with laptop memory do not help, it’s likely that your problem is related to the motherboard.

The laptop was dropped and the screen is white now. Video on the external monitor works fine but the laptop screen shows only white color, nothing else.

Possible cause:

1. Video cable disconnected from the LCD screen.
2. Damaged LCD screen.

Possible troubleshooting steps and repair solution:

1. Check connection between the video cable and LCD screen. It’s possible that the video cable got disconnected when the laptop was dropped. Try reconnecting the video cable first. Make sure the video cable seateed all the way down into the connector on the back of the LCD screen.

2. If reconnecting the cable doesn’t help, most likey you damaged the LCD screen. The screen has to be replaced.

The laptop turns on and the power LED lights up but nothing appears on the screen. The external monitor also shown no video. Unplugging the laptop from AC power and removing the battery for a minute doesn’t help.

Possible cause:

1. Memory failure.
2. Motherboard failure.
3. Processor failure.

Possible troubleshooting steps and repair solution:

1. Try reconnecting memory modules.

Try removing memory modules one by one and test the laptop with each memory module separately. This way you can find the faulty memory module.

Try installing memory modules into different slots on the motherboard. If the laptop works with both modules in one slot, but not in the other slot, the second slot is bad.

If you have only one memory module installed, try replacing it with a known good module.

2. If reconnecting and replacing memory modules doesn’t help, most likely there is a problem with the motherboard.

3. Could be bad processor, but processor failures are very rare. The processor would be the last thing to blame.