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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August 14th, 2009 at 4:26 pm
I have Sony SZ1 XP/C, to which the (LED) screen went dim, but the image was visible. So I though it’s either inverter board or backlight or some of the cables there. I opened the top part of the laptop, looked a bit, could not figure out much and closed it.
After this, it went entirely dead. I have no idea what I could have broke, I don’t recall scratching something. Any ideas what could have gone wrong, what to check..?
August 8th, 2009 at 4:13 pm
gorio,
It depends on the laptop model. Most laptops have integrated video card, it’s when the video card is a part of the motherboard. If that’s the case the video card cannot be removed.
August 8th, 2009 at 4:05 pm
LuisVen,
Unfortunately, there is no much further testing you can do. It’s either bad motherboard or video card and at this point you’ll have to guess.
I think it’s bad video card because you are getting beeps. When you have a bad motherboard, usually it doesn’t give you any error messages.
August 8th, 2009 at 1:49 pm
pradeep,
Sorry, cannot help you. I don’t work on the component level. In cases like that I just replace the whole motherboard.
August 8th, 2009 at 1:43 pm
billy,
You’ll have to test the power switch for continuity. Make sure the laptop is powered down. Set your multimeter to make noise when the circuit is closed.
Connect the multimeter probes to the prongs on the switch and press on the button. If the multimeter makes noise when you press on the button, most likely the button is working fine.
Do you get any activity from the laptop when you press on the power button at all? The hard drive noise, DVD drive light, etc..?
Do you know if the power switch button is located on a separate board or it’s on the motherboard?
Try replacing the power switch board if it’s a separate board, shouldn’t be very expensive.
August 5th, 2009 at 1:31 pm
i have a gateway laptop that will not power up i have took the motherboard out and tested the jack and there is 19v i have also tested the prongs where the battery goes and they are also getting power i tried the multi metre on the power switch and seems to be dead there are 4 prongs on the power switch i put the meter on these 4 prongs and got nothing is this the wright way to test the switch and can i buy pass the switch to see if it will start up
i now have a packard bell with the same problems sureley this cannot be right could you point me in the right direction to get them up and running many thanx
August 5th, 2009 at 6:32 am
my laptop is not working i connect the dc jack the power led was blinking(on and off each second) and i saw the mother board one 14 pin ic is burnd i connot identify the ic part details. so please help to wack up my laptop. (MY LAPTOP DETAIS compaq armada E500 PENTI III )
August 3rd, 2009 at 2:42 pm
Dead motherboard? Yea, that’s why I’m here, I was hoping to get some board level trouble shooting info. I didn’t know it was gonna be this basic common sense stuff. Let me know if you ever get to the hardcore stuff. Thanks.
August 2nd, 2009 at 2:28 pm
Hi friends …
I have a Toshiba Qosmio F45-AV425. My problem is similar to the one being discussed in this post: When I press on the power button, the laptop starts, the LEDs work properly but noting appears on the screen. I hear two beeps and immediately cooling fan stops but the LEDs continue on, then I have to turn off the computer.
I followed step by step cj2600´s instructions: I used an external monitor, change the memory for good one, disconnect each of the components (DVD, modem card, wi fi card, keyboard) and cables (mousepad, multimedia buttons, etc.), trying to turn on the computer in each case, but nothing. Finally, I disassembled my laptop completely, connect the motherboard to an external monitor and power supply, but when I press the power button, it showed the same problem.
My motherboard has a video card Nvidia Geforce 8600M GT and an Intel Centrino Core 2 Duo 2.0 GHz I believe the problem is on the motherboard or the video card, What another test can I do?
August 1st, 2009 at 4:25 am
how can i upgrade video card on my laptop?