When the laptop is turned on, the screen remains completely black/blank and the cooling fan starts running at full speed. The fan runs at unusually high RPM until you power down the laptop.

Possible cause:

Motherboard failure.

Possible troubleshooting steps and repair solution:

Most likley this problem is related to the motherboard failure and the motherboard has to be replaced.

The laptop screen goes darker when the power adapter is plugged in. When the adapter is unplugged, the screen becomes brighter.

Possible cause:

Wrong setting in the power management software or BIOS.

Possible troubleshooting steps and repair solution:

Most likely the problem is related to the settings in the power management software or BIOS.

Find the power management utility installed on your laptop and check the LCD screen brightness settings. Apparently, the LCD screen brightness settings are higher for the battery mode. Increase LCD screen brightness settings for the AC mode and the problem will be fixed.

In some laptops you can change LCD screen brightness in the BIOS menu. Enter the BIOS menu and make sure the LCD brightness is set to maximum for the AC mode.

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 image on the screen is very dark after the laptop fell of the desk. You still can see the desktop background picture and icons if you look very closely but the screen has no light.

Possible cause:

1. Video cable got disconnected from the screen inverter board.
2. Damaged backlight lamp inside the LCD screen.

Possible troubleshooting steps and repair solution:

1. It’s possible the screen is very dark because the video cable got disconnected from the screen inverter board. As a result, the backlight lamp gets no power from the inverter board and remains off even when the laptop is turned on. Disassemble the display panel and try reseating the video cable connectors on the inverter board.

2. If reseating the video cable connections doesn’t help, most likley the screen backlight lamp was damaged when the laptop fell off. The backlight lamp is located inside the LCD screen and it’s very hard to replace just the lamp. I would suggest replacing the entire LCD screen which comes with a new backlight lamp.

By the way, you still should be able to use the laptop with video output on the external monitor.

The laptop backlight stopped working without any reason. The screen was working fine a while ago but now it’s very dark. The image is still on the screen but it’s barely visible. When the laptop rebooted, the screen remains very dark.

Possible cause:

1. Backlight inverter failure.
2. Backlight lamp failure.

Possible troubleshooting steps and repair solution:

1. Most likely this is related to the backlight inverter failure. The inverter board is installed inside the laptop display panel and in most models mounted below the LCD screen. When the inverter board fails, the laptop screen goes completely dark and the data on the screen becomes barely visible. There is a good chance to fix the backlight problem by replacing the inverter board.

2. If a new inverter doesn’t fix the problem, apparently you have a faulty backlight lamp inside the LCD screen. Replace the LCD screen.

It is possible to replace just the backlight lamp but it’s not easy and should be done by an experienced technician.

The laptop screen turns on properly then flickers and goes black. If you restart the laptop the failure sequence repeats.

Possible cause:

1. LCD screen inverter failure.
2. LCD screen backlight lamp failure.

Possible troubleshooting steps and repair solution:

When the laptop LCD screen flickers and goes black, most likely the problem is related either to the screen inverter or backlight lamp inside the screen.

You cannot tell which one is failing without testing the laptop with another working inverter or backlight lamp. Both parts have very similar failure symptoms.

If you have to guess, replace the inverter board first. If it doesn’t help to fix the problem, replace the LCD screen. It’s possible to replace just the backlight lamp inside the screen but it’s not easy and should be done by an experienced technician.

The laptop screen goes black for no reason. The laptop starts properly and the screen works properly for some time, but later it just goes black. After you restart the laptop, the screen goes black after some time again.

Possible cause:

1. Screen inverter failure.
2. Screen backlight failure.

Possible troubleshooting steps and repair solution:

Most likely this problem is related to the screen inverter failure. The inverter board works as a power supply for the backligh lamp. When inverter fails, the screen goes dark. You still can see a very faint image on the screen but it’s very dark. Try replacing the inverter board first. It’s located inside the display panel below the LCD screen.

If a new ivnerter doesn’t fix the problem and the screen still goes dark after some time, most likley you have a faulty backlight lamp inside the LCD screen. If that’s the case, you’ll have to replace the screen. It’s possible to replace just the backlight lamp but it’s not easy and should be doen only by an experienced technician.

When inverter or backligth lamp fails, you still should be able to use the laptop with video on the external monitor.

The screen gets dimmer when AC adapter is plugged into the laptop. The screen is bright when laptop runs on the battery power.

Possible cause:

LCD brightness settings in the power management software or BIOS setup menu.

Possible troubleshooting steps and repair solution:

Most likely this problem is related to the LCD brightness settings in the power management software or BIOS setup menu.

1. Connect your laptop to the AC adapter. Try increasing LCD screen brightness through a shortcut on the keyboard.
For Toshiba laptops hold down the Fn key and press on F6/F7 keys to increase/decrease the brightness.
For Dell laptops hold down the Fn key and use Up/Down arrow keys.
For IBM laptops hold down the Fn key and use Home/End keys.
For HP laptop hold down the Fn key and use F7/F8 keys.

Some other brands may have different keyboard shortcuts for increasing/decreasing LCD screen brightness.

2. In some brands you can adjust screen brightness in the BIOS setup menu. Enter the BIOS and make sure the brightness is set to 100% for AC mode.Correct settings if needed.

3. Check setting in the power management software installed on your laptop. Make sure the screen brightness is set to 100% for AC mode. Correct settings if needed.

The laptop stars with a pinkish screen. All white colors have a light pink tint to it. After a while the screen goes completely dark. If you restart the laptop it starts with a pinkish screen again but after some time it goes dark again. Time intervals between screen failures may vary after each restart. If you reduce the screen brightness, the screen stays on for a longer time.

Possible cause:

Backligh lamp failure.

Possible troubleshooting steps and repair solution:

Most likely this problem is related to the backlight lamp failure. The backlight lamp starts failing because it’s getting old.
You can replace the backlight lamp inside the LCD screen which should be done only by an experienced technician.
Alternatively, you can replace the entire LCD screen. This repair is less time consuming and could be done at home by yourself.

The laptop starts but the screen remains very dark. You can hear normal startup sound even though the screen is almost black. If you look on the screen very closely under the bright light you can see outlines of normal desktop image.

Possible cause:

1. Inverter board failure.
2. Screen backlight failure.

Possible troubleshooting steps and repair solution:

1. Most likely this problem is related to the inverter board failure. The inverter board works as a power supply for the backlight lamp inside the LCD screen. When inverter fails, the laptop start normal but without backlight on the screen. As a result, the image on the screen is so dark that you can barely see the desktop image. You have a good chance to fix the problem by replacing the inverter board.

2. If a new inverter board didn’t fix it, most likely you have a faulty backlight lamp inside the screen. You can try replacing the backlight lamp but it’s not easy and should be done only by an experienced technician. Otherwise, replace the whole LCD screen.