In this post I’ll explain how to troubleshoot a dead laptop and find the problem. The following troubleshooting tips are not model and brand specific, they should work for most laptops.
Let’s take a look at two different scenarios.
Example 1. The laptop is absolutely dead.
When you plug in the power adapter and press on the power button, there is no signs of life at all. The laptop will not make usual noises, LEDs will not light up, the fan will not spin, the screen is blank and black, etc… In short, the laptop is dead.
What you can do in this case?
1. Make sure the wall outlet is working and the laptop DC adapter is getting power from the outlet. Try another wall outlet.
2. Test the laptop DC power adapter, make sure the voltage output is correct. You can test the DC power adapter with a voltmeter.
3. Let’s say the DC adapter is fine and the adapter outputs correct voltage. In this case unplug the power adapter from the laptop, remove the battery, wait for 1-2 minutes, plug in the adapter and try turning on the laptop again.
OK, you tested the adapter and it’s bad. If you decide to replace the original DC adapter with a generic one, you’ll have to follow this rule:
The voltage output on your new adapter has to be exactly the same as on the original adapter. The amperage on the new adapter could be the same or higher.
If nothing helps and the laptop is still dead, apparently the motherboard is fried or there is a problem with the DC power jack. It’s possible the DC power jack is broken and the motherboard is not getting any power from the adapter. In this case you’ll have to disassemble the laptop and replace the power jack. Check out this guide for fixing laptop power jack.
Example 2. When you plug the DC power adapter and press on the power button, the laptop starts making normal noises, the LEDs work properly but noting appears on the screen. The laptop will not start.
First of all, take a closer look at the LCD screen. Look at the screen under bright light. It’s possible that the image is still on the screen but it’s very faint. If that’s the case, check out these tips for troubleshooting laptop with backlight failure.
If there is no image on the laptop LCD screen, test the laptop with an external monitor. Connect an external monitor to the VGA port on your laptop and turn the laptop on. You can toggle video output between the internal LCD screen and external monitor by pressing 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.
Let’s say the external monitor works fine but the internal LCD screen has no image at all. If that’s the case, your problem could be related to the LCD screen or the video cable. Also, make sure the video cable makes good connection with the motherboard and the LCD screen. Try reconnecting, reseating the cable.
In my case, both internal and external monitors were absolutely dead. Neither of them had image. That means the problem is not related to the LCD screen or the video cable. From my experience I know that this problem could be related to the laptop memory.
Try reseating the memory module, maybe it’s not making good connection with the memory slot. Try cleaning contacts on the memory module with pen eraser. Try moving the memory module into another slot. Try replacing the memory module with another known good module, it’s possible that your original module is dead.
If you have two memory modules installed you can try removing them one by one, it’s possible that one of the modules is bad. Try installing different memory modules into different memory slots.
In my case reseating, swapping the memory module didn’t help. I was pretty confident that my problem is not memory related and I moved on.
Try removing battery, hard drive and DVD drive and turning on the laptop without these components.
Also, try turning on the laptop with an external monitor when the video cable is unplugged from the motherboard. If the laptop start with video on the external monitor, apparently there is something wrong with the laptop display panel.
In my case removing the hard drive and DVD drive didn’t help. Unplugging the video cable didn’t help either.
I continued taking my laptop apart piece by piece and tested it after each step.
I removed wireless card, modem, disconnected the keyboard but it didn’t help.
I still wasn’t able to boot the laptop with video on the external monitor.
Finally, I disassembled the laptop and removed the motherboard.
On this picture you see my final test. The motherboard has been removed from the base and I assembled basic barebone system on my bench.
1. Motherboard. Like on most laptops, in my case the video card is integrated into the motherboard
2. CPU with heatsink and cooling fan.
3. Known good memory module.
4. The power button board witch I need to turn on the system.
5. Working DC power adapter.
Still cannot get any video on the external monitor. The system turns on, the cooling fan starts spinning but there is no video.
At this point I’m 95% sure that the motherboard is dead. CPU failures are not very common, so it must be bad motherboard.
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July 29th, 2008 at 9:35 pm
gil h. lariosa,
Did you test the laptop with an external screen? The image disappears from both screens, internal and external? Could be memory problem. Try reconnecting the memory module. Test your laptop with another working memory.
July 28th, 2008 at 1:37 am
ihave my laptop when i press the power on the led is ligth but ther is no emage on lcd . sometimes when i push thepower on the have image and run normaly . when i shutdown the computer and re start it again no moreimage on the lcd .can you help me on my problem. anyway mylaptop is syntax model a530.
July 21st, 2008 at 5:21 pm
Dear all,
I am facing a strange problem. My Laptop is totally dead (Not responds anything after pressing power button) but when i plug the adapter the battery LED is emitting and showing its full charge color. What are possible problems? Can you give some solutions?
July 20th, 2008 at 12:18 pm
Faraz,
Could be power jack related problem. Maybe the jack is not making good connection with the motherboard and has to be resoldered.
Check out this post, maybe you have the same problem with your laptop.
July 20th, 2008 at 12:15 pm
David Kaunang,
Check out the Laptop Service Manual Category on the right side of the website. I post links to service manuals and disassembly instructions in this category.
July 17th, 2008 at 12:14 am
Hello,
I have a problem with my dell latitude d610, it operates normally without any problem, and then all of a sudden I get the message that my ac adapter has been disconnected and I am on battery power now, but I did not disconnect it.
It keeps discharging and starts working again whenever it feels like, maybe after 2 days or maybe after the battery has discharged by 90 %.
During this time I dont move the laptop or try to fix it it just stops charging and startgs again by itself.
also during this period, the remaining battery life is show as something like 1027:16 hours remaining.
can you please tell me what may e the problem with my laptop?
July 16th, 2008 at 1:29 am
Hi, i’ve got the problem just like the one that you trying to explain with this guide, can you please help me ..
how to open the laptop, just like you did on this guide? sorry for my bad english. hope you understand. Thanks.
July 14th, 2008 at 10:19 am
Paul Gys,
Here’s an update for my comment 13 and maybe some help to your comment 9.
Today I had to troubleshoot a Toshiba laptop with the backlight failure.
Failure symptoms:
The laptop starts but there is no backlight. Sometimes the backlight flickers on and off. After a while it goes off completely. I still can see the image but it’s very dark.
Also, there is a constant buzzing noise coming from the inverter.
Troubleshooting steps:
I removed the display bezel, so I can access the inverter board. I unplugged the LCD screen backlight from the inverter board and connected by test backlight lamp. Still same problem! My test backlight was barely glowing on one end and the inverter was buzzing.
I installed new inverter and it fixed the problem. The LCD screen is bright again.
July 13th, 2008 at 11:23 pm
Kat,
Apparently water damaged the motherboard. I cannot tell you what is wrong without taking a closer look at the motherboard.
July 13th, 2008 at 11:21 pm
Paul Gys,
First of all, check all brightness related settings. On some laptops you can change brightness even in the BIOS setup menu. Make sure it’s not just settings related issue.
If the backlight lights up but barely glowing, probably the backlight lamp is dying and has to be replaced.