Problem 1.
Computer doesn’t turn on at all.

When you plug the AC adapter into the laptop, there are no lights turning on at all. When you push on the power button, nothing happens. The laptop appears to be completely dead, makes no sounds, no indications of life.

Possible problem:
– The AC adapter failed and the battery has no charge left. In this case test the AC adapter with a voltmeter. If it’s dead, replace it with a new one.
– DC jack failed and the motherboard doesn’t receive any power from the adapter. In this case the DC jack has to be replaced.
– Motherboard failed. The motherboard has to be replaced, if it’s not too expensive. Otherwise get ready to buy a new computer.

Here are some tips for testing AC adapter and DC jack.

Also, make sure to read step-by-step instructions for troubleshooting dead laptops.

Problem 2.
Screen is blank.

The laptop turns on, power LED lights up, cooling fan works but nothing appears on the screen. The screen is completely black and blank. There is no image on the screen at all.

Possible problem:
– This can be memory failure. It’s possible one of the memory modules failed. In this case you can try reseating memory modules to make sure they are making good contact with the slot. You can try removing memory modules one by one and test the laptop with only one module installed. You can try replacing memory modules.
– If reseating/replacing memory doesn’t help, try removing the hard drive, DVD drive, modem, wireless card, keyboard, etc… In other words, disassemble the laptop to bare minimum and test again. If the laptop still doesn’t turn on, most likely you have failed motherboard or processor.

Read this guide for bare bone system troubleshooting.

Problem 3.
Laptop turns on and off repeatedly.

The laptop turn on without showing any image on the screen. After a few seconds it turns off by itself. Then it turns on and off again.

Possible problem:
Most likely this is motherboard failure. You can try reseating/replacing memory as I described in the Problem 2. If it doesn’t help, probably the motherboard failed.

Problem 4.
Laptop makes noise while running.

The laptop turns on and everything works fine, except it makes some constant weird grinding or rattling noise.

Possible problem:
In most cases this noise is coming from the cooling fan or hard drive. Take a closer look at the cooling fan.

If the fan doesn’t spin but the the laptop makes noise, probably it’s coming from the hard drive. Back up all personal data as soon as possible and replace the hard drive.

Also, you can remove the hard drive and stat the laptop. If the laptop still makes noise, most likely it’s bad fan.

Problem 5.
Laptop shuts down or freezes.

The laptop runs properly but after a while it freezes or shuts down without any warning. When it happens, the bottom feels hot. Also, the cooling fan runs louder than usual.

Possible problem:
Most likely this is heat related issue. It happens because the fan heat sink is clogged with dust and the processor not cooling down properly. Cleaning the fan and heat sink from dust should fix it.

Here’s how you fix heat related problems.

Problem 6.
Battery not charging properly.

The battery stopped charging properly. It doesn’t charge at all or charges only after you adjust the position of AC adapter plug inside the power connector.

Possible problem:
– Failed battery.  If it doesn’t charge completely try reconnecting the battery first. Also, try running the laptop just from AC adapter with battery removed. If it runs fine from AC adapter, most likely it’s either bad battery or failed motherboard. Try replacing the battery first.

– Failed DC power connector. If the battery charges only after you adjust the position of AC adapter tip inside the connector, most likely this the DC jack failed.

Here are some tips for charging problems.

Problem 7.
Screen light fails.

The laptop starts properly but after a while the screen light turns off. The image still appears on the screen but it’s very dark.

In some cases the screen light never starts and all you can see is a very faint image.

Possible problem:
Most likely it’s either failed screen inverter or backlight lamp (CCFL) failure.  When either one fail, the backlight stops working.

In order to troubleshoot this, you’ll need some spare parts: either new working inverter or known good backlight lamp.

Read how to troubleshoot backlight failure.

Problem 8.
Strange or garbled image on the screen.

The laptop turns on properly but has a distorted or garbled image on the screen.

Possible problem:
– The graphics card failed. First of all, test your laptop with an external monitor or TV. If you see the same garbled image on the external screen, most likely the graphics card failed.
– If the problem appears only on the laptop screen, this can be related to one of the following: poor connection between the video cable and motherboard or screen. Also can be failed video cable or screen.

Here are examples of failed video and explanations how to narrow down the problem.

Also read why display shows strange colors.

Problem 9.
Some keyboard keys stopped working.

Some keyboard keys do not work at all or type wrong characters.

Possible problem:
Most likely the keyboard failed and they are not repairable. Read how to replace the keyboard.

Problem 10.
Keyboard has missing or broken keys.

A key got separated from the laptop keyboard.

Problem solution:
If a key separated from the keyboard, it’s still possible to fix it.
If you have many keys missing, probably it makes sense to replace the whole keyboard.

Read how to attach a key back .

Problem 11.
Repetitive beep sound on startup.

You turn on the laptop but there is no video on the screen. Instead, it starts making repetitive beeping sound. In some cases you can “fix” the problem temporarily if you press on the keyboard keys.

Problem solution:
Most likely you have stuck keys. In this case you’ll have to replace the keyboard.

Problem 12.
Liquid spill.

You spilled something on the laptop and it’s stopped working.

Problem solution:
Liquid spills are very dangerous and unpredictable. If it happened, turn off the laptop ASAP, remove the battery and do not use it until all internal parts are inspected for liquid damage.
It’s sill possible to make it work again.

Read how to deal with liquid spills.

In this post I explain some basic troubleshooting techniques in case if your screen started showing strange or incorrect colors.
You have to know how to disassemble your computer in order to use following troubleshooting techniques.

TEST WITH EXTERNAL MONITOR

The main troubleshooting step is testing the video output on an external monitor (or TV). You can connect your laptop to an external monitor using VGA cable, DVI cable, HDMI cable or S-Video cable, it depends on a type of connector you have.

Most models have a VGA connector, so it would be the most common way to connect.

Some laptops detect external monitor automatically and start showing image on both screens right from startup.
Other models can detect the monitor but display image only on one screen (internal or external). In this case you’ll have to switch video between internal and external using the Fn key and one of the F* keys in the top row of the keyboard. This combination varies for different brands, for example it’s Fn+F5 for Toshiba, Fn+F4 for HP, Fn+F8 for Dell, Fn+F7 Lenovo etc…

WHAT VIDEO ON EXTERNAL MONITOR CAN TELL?

If both, the internal screen and external monitor (or TV) show strange or incorrect colors or any other image distortion, this is the graphics card failure.

If only the internal screen shows bad video but external image appears to be normal (as in my example), the problem is somewhere inside the laptop display. This could be bad connection, bad LCD cable or bad LCD screen.

Let’s narrow down the problem one by one.

TRY RESEATING LCD CABLE CONNECTOR ON MOTHERBOARD

The screen receives data signal from the motherboard via LCD cable. If the LCD cable not making good connection with the motherboard, it might cause image or color distortion on the screen. Try reseating the LCD cable connector and see if it fixes the problem. Make sure the LCD cable connector plugged correctly.

In most laptops the LCD cable connector located under the keyboard bezel (aka keyboard cover). If it’s not there, most likely you’ll find it somewhere under the keyboard.

WIGGLE THE LCD CABLE

The LCD cable runs inside the display panel, under the screen. For this test it’s necessary to disassemble the display, so you can access the cable.

A pinched or damaged wire inside the cable also can cause color distortion.

Wiggle the cable while the laptop is running. If moving the cable affects image on the screen in any way (it starts shown different colors, lines, or image clears to normal, etc…) most likely the cable is defective and has to be replaced. Try replacing the cable.

On the other hand, if moving the cable doesn’t affect image at all, most likely the cable is good and you have a failed screen. In this case you’ll have to it with a new one.

APPLY SOME PRESSURE TO THE DISPLAY

Try applying some reasonable pressure to the top part of the display assembly. Squeeze it with your fingers.

If the screen starts showing different colors, lines, or clears to normal when you squeeze the top part of the display panel, most likely this is screen failure. In this case you’ll have to replace the screen.

Also, you might be interested in the following posts:

Troubleshooting backlight failure.
How to test screen inverter.
Bad video on the screen. What is wrong?
Fix video problems.

Example 1.

Laptop shuts off when AC adapter unplugged.

When you move the cursor arrow over the battery icon while the laptop is connected to AC adapter, it show the remaining charge and says “charging”.

The power meter utility (if available) also shows that battery is connected and charging.

But… as soon as you unplug the AC adapter, the laptop shuts off completely.

Possible problems:
1. The battery not seated correctly. Try reconnecting it.
2. The battery contacts got dirty or oxidized and it’s not making good connection with the motherboard. Apply some electronic contact cleaner on the contacts.
3. If reconnecting the battery doesn’t help, most likely it’s bad and has to be replaced.
4. If you replaced the battery but the problem still exists, this is motherboard related failure. Apparently the charging circuit on the motherboard failed. In this case the whole motherboard has to be replaced (or repaired on the component level).

Example 2.

The battery not detected by the laptop.

There is a red cross on the battery icon.

If you move the cursor arrow over the battery icon, it says “no battery detected”.

Possible problems:
1. Most likely the battery is bad. You have a very good chance to fix this problem by replacing it with a new one.
2. If replacing the battery doesn’t help, this is motherboard related failure. The motherboard has to be replaced (or repaired on component level).

Example 3.

The battery discharges very quickly after it reaches some critical point.

The battery detected by the laptop and charges properly to 100%.
When you unplug the AC adapter, it take normal time to discharge until some critical point (let’s say 80%) but after that the battery discharges very quickly to 0%.

Possible problems:
This is battery failed. It has to be replaced with a new one.

Example 4.

The battery charges only if the power plug positioned correctly.

You have to wiggle the power plug in order to charge the battery. After you find the right position, it charges properly.

Possible problems:
1. AC adapter failure. The AC adapter power cable is damaged. Here’s how to test your AC adapter.
2. If the AC adapter works fine, most likely this is power jack (connector where you plug power adapter) failure. In this case the power jack has to be replaced.

The inverter failure is very similar to the backlight lamp failure. In both cases the screen gets very dark and the image becomes very faint, barely visible under a bright light.

There is only one reliable way to test the inverter – replacing it with another one and see if the screen lights up after that.

Alternatively, you can connect a new backlight lamp and see if your presumably bad inverter lights it up.

In most cases I go with the second method – using my test backlight lamp. Why? Because the same backlight lamp will work with many different inverters as long as they have matching connectors.

Usually the inverter is mounted inside the display panel below the screen. In most cases you can access it after you remove the display bezel. The inverter has connectors on both ends. The left side connects to the LCD cable. The right side connects to the backlight lamp which is mounted inside the screen. Check out this display diagram.

To make sure that inverter gets power from the motherboard (via the LCD cable), you can test it with a voltmeter. In my case I connected the “+” lead of the voltmeter to the pin 1 and the “-” lead to the ground trace around the screw hole. I got about 19.4V DC on that side of the board, so it’s getting power from the motherboard.

WARNING! If you accidentally short something on the inverter while testing, you can damage it. Proceed on your own risk! Not sure? Don’t do that!

So far we know the inverter is getting power from the motherboard, but the screen still has no light. Apparently, it’s either bad inverter or failed backlight lamp.

Now let’s test it with a known good backlight lamp.

1. Unplug the screen backlight cable from the right side of the inverter.
2. Connect a known good backlight lamp.

Turn on the laptop.
1. If the test backlight turns on, the lamp inside the screen is bad. In this case you’ll have to replace the screen. Also, you can replace the backligth lamp which is not easy and not recommended.
2. If the test backlight doesn’t turn on, most likely we have inverter failure. Replace it and test the laptop again.

There are two different types of backlight connector, you can see them on the picture below. The top one (big) is not as common as the bottom one (small). I mostly use lamps with a small connector.

IMPORTANT! When you buy a new lamp for test, make sure the connector fits your inverter.

On the following picture you see how I’m testing the laptop with a new lamp.

Related articles:

Troubleshooting backlight failure.
Screen shows strange colors.
Troubleshooting video problems.

Lets figure out step-by-step how to troubleshoot and  and fix the problem.

First of all, I assume that your new LCD is compatible with the original one. If the screen looks identical, it doesn’t exactly mean it’s compatible. Double check the compatibility between the original and new LCDs.

Troubleshooting LCDs with CCFL (backlight lamp)

The old style screens have a backlight lamp inside and require an inverter board which is usually mounted on the lower part of the display assembly, as you can see on the following picture.

On the following picture you can see how the screen connected to the laptop. Also, check out this display diagram.

The video cable routed from the motherboard to the display through one of the hinges. Somewhere close to the hinge, the cable splits. The wider end connects to the screen (supplies data signal) and another one to the inverter board (supplies power for inverter).

If your new screen lights up but has no image make sure the video cable plugged correctly. It’s possible that during the reassembly process you accidentally pulled the cable from the connector.

Reconnect the cable, secure the connection with sticky tape and test the laptop. There is a chance that now the screen will work properly.

The video cable has to be seated properly, all the way down into the connector.

Some older LCDs have very thin pins inside the video connector as it shown on the following picture.

Take a look inside, make sure there are no damaged (bent) pins. It’s possible that you accidentally bent them while trying to plug in the cable.
You can straighten bent pins with a very small screwdriver. Be careful, they are very fragile.

Fortunately, most newer LCDs have a different type of connector, without any pins inside.

OK, you have reseated all cables but it still doesn’t work. What’s next?

If your original screen was cracked but undamaged areas still work and show some image, you can use it to test the laptop.

Disconnect the new LCD and install the old damaged one back in place. If the old screen still works but the new one doesn’t, your new screen is defective. Send it back to the seller for a replacement.

Here’s another scenario. The new screen kind of works. You can see a very faint image but there is no backlight.

Disconnect the new screen from the inverter board and plug in the old screen instead (I assume it has working CCFL), as it shown on the picture below. If the original screen lights up, apparently the new screen has defective backlight lamp.

Troubleshooting LED-backlit LCDs

Newer LED-backlit LCDs have only one cable connected to it. This cable supplies data signal and power for LED backlight.

If your new screen doesn’t work, check the connection first. Make sure the cable seated properly, all the way down into the connector.

You can test the computer with the old, partially working screen, as we did earlier. If the old one still works, but the new doesn’t, your new screen is defective or not compatible.

Also, you might be interested in how to troubleshoot bad video.

Let’s take a look at different failure scenarios.

Example 1. The computer is absolutely dead. 

When you plug in the AC adapter and press on the power button, there are no signs of life at all. It appears to be dead.

What you can do ?

1. Make sure the wall outlet is working and the AC adapter is getting power from the outlet. Try another wall outlet.
2. Test the AC adapter, make sure the voltage output is correct. You can test the adapter with a voltmeter.
3. If the adapter is good, try reconnecting the battery. Remove the battery, wait for 1-2 minutes, plug in the adapter and try turning it on again.

If the adapter doesn’t pass the test with a voltmeter, replace it with a new one and test the computer. I always recommend buying an original replacement adapter from the manufacturer, not a generic one.

There could be more than one adapter available for your model.
The voltage output on your new adapter must be exactly the same as on the old one. The amperage, on the other hand, can be the same or higher.

If previous troubleshooting steps didn’t help, it’s possible your computer has a problem with the motherboard or DC power jack. In this case it’s necessary to disassemble the laptop and test the DC jack.

Example 2. The computer turns on and makes normal startup noises, the LED lights turn on but noting appears on the screen.

First of all, take a closer look at the screen under bright light. It’s possible the screen shows the image but it’s very faint. In this case you’ll have to troubleshoot the backlight failure.

On the other hand, if the screen shows no image at all, test the laptop with an external monitor (or TV) connected to the VGA port or DVI port or HDMI port.

You can toggle video output between internal and external modes by using Fn keys:
– Fn and F4 keys simultaneously on HP laptops
– Fn and F5 keys on Toshiba laptops
– Fn and F7 keys on IBM laptops.
Other laptops may use different key combinations.

If the external monitor works fine but the internal screen has no image at all, the problem can be related to:

– Poor connection between the video cable and screen or motherboard. Try reconnecting the video cable on both ends and check out if this helps.
– The screen failed. Replace it with a new one.
– The video cable failed. Replace it with a new one.
– The motherboard failed.

If both, the internal and external monitors show no image, the problem can be related to:

– Failed memory (RAM).
– Failed motherboard.

– Try reconnecting the memory module, maybe it’s not making good connection with the slot.
– Try cleaning contacts on the memory module.
– Try moving the memory module into another slot.
– Try replacing the memory module with another one.

If you have two modules installed you can try removing them one by one, it’s possible that one of the modules failed. Try moving modules from one slot to another.

If changing or reseating memory doesn’t help, you can try this:
Removing the battery, hard drive, DVD drive and other components you can easily access. Try turning on the laptop without these components installed.

It’s possible one of them failed and it’s preventing the entire computer from starting up properly.

Also, try turning on the laptop with an external monitor while the video cable is unplugged from the motherboard.

If external image appears after you disconnected the video cable, apparently there is something wrong with the cable. Replace it with a new one.

If the computer is still dead, try removing other internal components (wireless card, modem, keyboard, etc…) and test it with an external monitor after each removed part.

The last step is testing the laptop as a barebone system.

On this picture you see my final test. The motherboard has been removed from the base and I assembled a basic barebone system on my bench.

The bare bone system includes:
1. Motherboard (like in most cases it has onboard graphics chip).
2. CPU with the cooling module.
3. Known good memory module.
4. The power button board.
5. Known good AC adapter.

If the system still doesn’t turn on, it’s either bad motherboard or failed CPU.

If you computer shows garbled or distorted image, check out this post.

First of all, I tested this laptop with an external monitor connected to the VGA port and the external monitor worked absolutely fine. I was able to get crystal clear image on the external screen even though the internal screen didn’t light up. If the external screen works fine, then most likely there is nothing wrong with the video card.

Notebook display assembly diagram

After that I took a closer look at the laptop LCD and noticed that the screen is not completely black. The laptop screen still works but the image is very very dull, you barely can see it. It means that the screen still gets data signal from the video card, but for some reason the backlight lamp doesn’t work.
From my experience I know that this problem can be related the lid close switch, faulty inverter board or bad backlight lamp. I checked them one by one.

If you have a similar problem, make sure the lid close witch moves freely. The lid switch is a small button located close to the LCD screen. This button triggers the hibernation or sleep mode when the screen is closed. If the lid close switch is dirty, it might get stuck inside the laptop case and cut off the power from the inverter board. The inverter board works as a power supply for the backlight lamp and if there is no power coming to the inverter board, the backlight lamp will not light up either.

In my case the lid button worked properly, it didn’t stuck inside the case. When I was pressing on the button very fast, I was able to light up the screen but only for a fraction of a second. The image wasn’t bright and it had a pinkish tone. A pinkish tone usually indicates a problem with the backlight lamp, not the inverter board.

Even though I suspected the backlight failure, I decided to test this laptop with a new inverter board just in case. But it didn’t help. The screen didn’t light up even after I replace the inverter board. So, I was right, this problem is not related to the inverter board.

Finally, I disconnected the screen backlight lamp connector from the inverter board and connected my test backlight lamp (I removed it from another cracked screen). You can find a new backlight lamp on eBay. Try to find a backlight with the connector already attached to it, so you can plug it into the inverter board. Make sure the connector on the backlight lamp is similar to the connector on your LCD screen.

As soon as I turned on the laptop, my backlight lamp lighted up. Yep, that’s the problem. The laptop screen has a faulty backlight lamp.

Here’s another laptop with backlight failure

This laptop video fails in a little bit different way. In this case the backlight lamp hasn’t failed completely.

The laptop starts with video on the screen but the background has reddish tone, the screen flickers and it makes noticeable buzzing noise coming from the backlight and inverter area. After a few minutes the backlight turns off by itself and the buzzing noise stops. When the backlight is off, the image on the screen is still visible but it’s very dark.

I removed the screen bezel and connected my test backlight lamp.

My test backlight works absolutely fine. The lamp doesn’t flicker and there is no buzzing noise. So, this laptop needs a new backlight lamp.

Situation 1.

The laptop appears to be dead. You plug the AC adapter but the LEDs (power light, hard drive light, battery charge light, etc…) do not light up and the laptop will not react at all if you press on the power button.

First of all in this situation check the AC adapter. You can test the output voltage with a voltmeter. If you cannot do that, find a known good AC adapter and use it for testing the laptop. It is possible the laptop appears to be dead because the AC adapter is bad (and the battery is discharged). If you know that the AC adapter is working properly and it outputs correct voltage but the laptop is still dead, most likely you have a power issue on the motherboard (or power board on some laptops) and it has to be replaced.
If you have to replace the AC adapter, make sure you use a correct one. The output voltage must be exactly the same as on the original adapter. The output amperage has to be the same as on the original adapter or higher, but not lower.

Situation 2.

When you plug the AC adapter the power LED and the battery charge LED light up. When you press on the power button the laptop powers up but will not start. There is no video on LCD or external monitor.

If the power LED lights up it indicates that the laptop is getting power from the AC adapter. Most likely there is nothing wrong with the adapter but just in case test it with a voltmeter to make sure the output voltage is correct.
Also try this. Unplug the AC adapter, remove the battery and wait for 1-2 minutes. After that plug the AC adapter ans try starting the laptop again. Sometimes this trick helps.
It also could be a memory related problem. Try reseating the memory module, just remove it from the slot on the motherboard and install it back. Try installing the memory module into the other slot (if it’s available). If you have two memory modules installed, try removing them one by one and start the laptop just with one memory module installed.
If the laptop starts fine with one memory module in both slots, but will not start with the second memory module in both slots, the second memory module is faulty. Replace the module.
If the laptop starts fine with both memory modules when they are installed in the slot A, but will not start with both memory modules installed in the slot B, the slot B is faulty and you’ll have to replace the motherboard or use only one memory slot.

Situation 3.

When you press on the power button, the laptop makes a series or short and long beeps and will not start up. There is no video on the screen.

In this situation test the memory module as I described in the situation2. Try installing a known good memory module. Most likely you are getting a beep error because of a faulty memory.

Situation 4.

You start the laptop. It sounds like the laptop is booting normally (hard drive LED is flashing) but there is no video on the screen

In this situation test the laptop with an external monitor. If the external screen works fine but there is no video on the laptop LCD, most likely there is a problem inside the laptop display assembly. Go to my previous post witch covers laptop video problems in more details.

Situation 5.

You start the laptop and it starts making repetitive clicking noise or grinding noise.

Most likely you hear this noise because of a faulty hard drive. You can remove the hard drive and start the laptop without it. If the noise is gone, the hard drive is your problem. Replace it.
If the laptop makes clicking or grinding noises and you still have video on the screen, you can run a hard drive test utility. I usually use Hitachi’s drive fitness test. This test is reliable and easy to use.

Situation 6.

The laptop boots into Windows ans works for a while, but after that it shuts down by itself without any reason or warning. You restart the laptop but the same problem appears again

Most likely it’s a heat related issue. Listen for the cooling fan, make sure it works.
Also this problem might appear because of a faulty memory module, try some tips from the situation 2.
The laptop still boots ans you still can see the screen, so you can run the memory test. I usually use Memtest86+. Run the memory test and if it fails, replace the faulty module.

Situation 6

The laptop starts normally but video on the screen has lines, some strange characters or other defects

It could indicate a problem with the laptop LCD screen, video cable, graphics card or motherboard. Here’s my previous post witch covers troubleshooting bad images on the screen in more details.

Related post: How to troubleshoot dead laptops.

It was Toshiba Satellite A70-S249 notebook with the following problem.
When I press on the power button, the laptop starts up as usual and a red Toshiba logo appears on the screen. After a moment the logo disappears and the screen turns black without any faint image and flashing cursor. The blue light around the power button stays on and fans continue to spin normal but nothing appears on the screen. I noticed that the hard drive LED blinks green on the startup and after that shows no activity at all. After a closer inspection I noticed that the screen is not completely black (like dead black), it didnâ€t have any image on it but it had a very faint backlight (I would say about 3-5% of normal brightness). I was able to see that there is some backlight after I pressed on the lid close switch and the screen turned to completely black.

Here are my troubleshooting steps that I went through to find the problem.
First of all, I replaced the memory module and didnâ€t get any changes. Removed the wireless card, still had the same problem.
After that I removed the hard drive and started the computer. This time I got something. The notebook successfully passed the Toshiba screen and started looking for a boot device. I got some activity on the screen. To make sure that the notebook itself works fine, I booted it from Knoppix (live Linux CD) and successfully loaded the Linux operating system to the desktop. So, thatâ€s the hard drive problem!
I installed the hard drive back in the laptop and tried to boot it again. The same failure occurred again; I got a black screen with a very faint backlight and no hard drive activity at all. I tested the hard drive with Hitachi DFT test and failed an advanced test. The problem is detected!
Finally I installed a new hard drive, reimaged the drive with a recovery DVD and got the laptop back up and running.

By the way, even though the customerâ€s hard drive failed the DFT test, I still was able to access it from another computer. The customer had important personal files on the failed drive. I connected it to our recovery desktop computer using IDE adapter. The “failed” hard drive was detected without any problem and I was able to recover the data.

Example 1.

Hereâ€s a picture of Satellite M55 LCD screen I made this morning. I got this video output as soon as I started the laptop. There were a lot of vertical lines, and they were changing color without any pattern. To me it looked like Northern Lights (never seen in real life) :). The external monitor worked fine.

As soon as I applied some tension to the screen it changed the pattern. Some horizontal lines appeared in the middle of the LCD.

Here’s the difference. When I torque the screen, the image appears but it’s distorted with some horizontal lines running across the screen.

Reseating the video cable didnâ€t make any change and the problem was fixed after I replaced the LCD screen.

Example 2.

I took this picture from Toshiba Satellite M65. I think that this example is very typical. One day you wake up, turn on the laptop and see one or a few hair-like vertical lines in different colors.

When you move the LCD screen some lines might disappear or more lines appear on the screen. A video output on an external screen would be perfect, without any lines. Unfortunately, these lines indicate a screen problem. Iâ€ve never seen this kind of video output caused by a bad video cable or bad FL inverter board. My laptop was fixed after I replaced the LCD screen.

Example 3.

The photo below comes from Toshiba Satellite 5205. The laptop displays identical vertical lines all over the LCD screen as soon as I turn it on. Sometimes these lines are red, sometimes they are blue, sometimes they become wider and change color to white.

The same pattern appears on the external monitor. It displays same vertical lines. When the same video defect appears on both monitors – internal LCD screen and external screen, then most likely it happens because of a bad video card. On some laptops the video card is integrated into the system board, on other models itâ€s a separate module.

In this example, the vertical lines were caused by a failed video memory on the system board. Iâ€ve tested the video memory with Microscope utility and it failed the test. In Toshiba Satellite 5205 the video memory is integrated into the system board. To fix the problem, Iâ€ll have to replace the board. (We do not have equipment to replace the memory module itself).

Example 4.

Hereâ€s another example of a bad LCD screen. My bad! It wasnâ€t the LCD screen problem.

As soon as I turned on the laptop, I was getting these reddish marks on the LCD screen but not on the external monitor. Reseating and replacing the video cable didnâ€t help. The problem disappeared when I installed my test LCD screen. Yes, for some reason I wasnâ€t able to reproduce the problem on my test LCD screen. But the reddish video appeared again as soon as I replaced the screen. I guess it happened because the system board had some kind of intermittent problem with onboard video or video connector. Long story short, I had to replace the system board and it fixed the problem. Yep, I misdiagnosed this laptop.

Example 5.

Hereâ€s one more example of a faulty LCD screen. The left half of the screen works just fine but the right side is completely white.

Example 6.

Here’s another laptop with a bad LCD screen. This time it’s a tablet PC.

Example 7.

This screen looks like the screen on the example 1. I hooked up an external monitor and the external video works perfectly fine.

Here’s the difference. When I torque the screen, the image appears but it’s distorted with some horizontal lines running across the screen.

After a few seconds the image washes away.

I had to replace the LCD screen.

Example 8.

This laptop displays inverted colors right from the startup. As you see, the Toshiba logo is light green instead of red. The background is light gray instead of black. The Intel logo should be blue on a white background but it is red on a black background.

When your laptop displays inverted colors as on the picture above, this is an indication of a bad screen. You’ll have to replace the screen.

Example 9.

Here are two more screens. In both cases this problem is related to the LCD screen, witch means the screen has to be replaced.

On the image below you see a white band running from the top of the screen to the bottom. This band appears right from the laptop startup and runs through the logo too.

On the following image only the left side of the screen is working properly. This problem is caused by faulty LCD screen.

Other post related to troubleshooting laptop video problems:

How to troubleshoot and fix laptop video problems
Taking apart notebook LCD screen
Replacing LCD screen inverter
The newly installed screen is not working