We may offen face
the same problem :when our laptop is dead. 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
press on the power button, there is no signs of life at all. The laptop
will not make usual noises, LED 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
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
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
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. may be
this arcitle is good for you.thank you for reading.
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