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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November 25th, 2008 at 10:21 am
cj2600,
I did check… With an ext monitor too I think. The only noises I hear are from the CD drive and from the fan and only for the first 5-7 seconds. Tried putting a LiveCD but still no HD light. And no light on the screen at all with or w/o ext monitor. I can’t open it any further due to badly stripped screws. Any suggestions? Is it safe to say that the mobo died? Are there any mobo testing tools? Thanks for the help
“Can you boot the laptop to the BIOS setup menu when the hard drive is removed? Maybe it’s bad hard drive?”
November 22nd, 2008 at 7:50 am
My Acer tablet laptop is not dead, but I’ve scanned the comments here and didn’t find anything about the problem of no longer getting video on the external monitor (but still can get video on laptop monitor). The display settings and drivers, the monitor and cable, have been checked OK. The problem seems related to the laptop VGA port. If so, is it repairable or does the motherboard need to be replaced?
Thanks for considering this problem.
November 20th, 2008 at 12:12 am
Haresh,
First of all, test your laptop with an external monitor attached to the VGA port on the laptop. If both internal and external monitors have no video, your problem could be related to:
1. Bad memory module. If you have two modules, try removing them one by one. Test the laptop with each module separately.
2. Bad motherboard.
November 20th, 2008 at 12:07 am
I have Toshiba A135 laptop, it has suddenly stopped working, the power n charging led come up when i power on the laptop the cpu cooling fan spins and stops in few seconds and no display comes on. There is nothing on the lcd, tried disassembling it step by step but still nothing worked, is the laptop motherboard dead or is it some other problem??
November 18th, 2008 at 2:23 pm
Oscar,
Can you boot the laptop to the BIOS setup menu when the hard drive is removed? Maybe it’s bad hard drive?
November 18th, 2008 at 2:21 pm
Jayson Darling,
Could be loose connection somewhere inside the laptop. In cases like that I usually try reseating internal cables and reconnecting removable components (RAM, DVD drive, HDD, etc…)
November 18th, 2008 at 2:11 pm
Jacob,
I guess it’s either bad AC adapter or bad motherboard.
November 18th, 2008 at 1:39 pm
need some help please…
i have a Toshiba Satellite M35X. LEDs work, normal noises, but no hd activity. Seems ot be charging just fine. I tried everything up to removing the video cable… I stopped there because a lot of the screws inside are really right and getting stripped.
Taking the ram out does cause a beeping… So is this a sign that the mobo is not dead? Should I just take it to a shop?
November 18th, 2008 at 9:43 am
As with comment 57 I am having the same problems with my FSC Amilo Li1705.
The wireless led & power led light up and then the laptop does nothing. After 5-10 hard restarts the lights for num lock, caps lock and scroll lock flash and the system starts. Once started the slightest shake and the laptop freezes, and the whole process starts again.
Laptop is 14mths old, FSC won’t have a bar of it – strict 12mth warranty. I did open it up from the access panel and found the CPU fan had lost a screw.
Sounds like its turned into a paperweight. Really don’t know if its even worth getting it fixed.
November 15th, 2008 at 8:42 pm
hey I need some help here,
I have a dell latitude c840, I think my battery or my adapter is gone. I got an exact replacement 2 months ago, it is the same adapter but battery is 6 years old. Okay my problem is that when the computer is plugged into the adapter and the computer is off, the battery LED blinks constantly a green light every second, no pauses. I take the battery out and the computer is plugged into the adapter and the computer will not turn on at all. I do not know what it could be. I took the whole damn computer apart like 20 minutes ago and the connection on the motherboard seems fine, it doesnt look borken or anything. Please help me. my email is jakelabelle@comcast.net.