Most common hardware problems

In this post I will summarize most common laptop hardware related problems and give some suggestions how to troubleshoot or repair them.

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.


175 Responses

  1. i’ve got a question:

    my laptop hangs sometimes and it won’t shut even if the battery is removed. What could possibly be the cause n what’s the solution to this? please help.

  2. cj2600

    @ Jacus aucamp,

    I check the ac adapter and that is working fine on my other dell but this one is dead.

    If the AC adapter works with another laptop, probably it’s not the adapter failure.
    Most likely it’s either bad DC jack or failed motherboard.

    I have most of my design work on my pc as im a graphic designer and i created my portfolio on this pc 2 years ago and now what do i do?

    In order to backup data from the laptop you can do the following. Remove the hard drive from the laptop and install it into an external USB enclosure. Connect the enclosure to any other working PC and get your files.

    By the way, if you have a SATA hard drive you can connect it directly to the PC. Most laptop SATA hard drives has same type of connector ad desktop hard drives.

  3. Jacus aucamp

    Hello,

    My Dell laptop just died on me an hour ago and it’s totally dead,no lights come on either,its just dead!
    I check the ac adapter and that is working fine on my other dell but this one is dead. I have most of my design work on my pc as im a graphic designer and i created my portfolio on this pc 2 years ago and now what do i do?
    Please help. Any other ideas.

    Thanks

    Jacus

  4. Samuel

    Excellent description.

    My problems is similar to what is shown above. The back light of my laptop screen goes off after few seconds while booting. Even though I can see the screen and give login password. I can see the desktop icons and work but have to have a closer look at screen or use other light like flash or torch. In two cases light comes back also. First, when I close and open the lid again and secondly, when the mouse pad is touched after the display of off as per time set (thus the lids is not moved in this case). In every case the light remains for not more that 4-5 seconds.

    Please suggest what can be the problem and if possible the cost involved.

    Thanks for the time and considering to reply.

  5. waskita

    very helpfull artcles….

    thank you so much

  6. Hi.

    I have a HP Pavilion dv7 laptop, I know that the battery has died in it. It was going bad for some time and now it’s dead. My issue is this. The Wifi won’t connect to my router although it see it and has a full signal. I sent it in for repair as it has a warranty on it, and they sent it back saying the dead battery was the cause.

    Is this true, can a dead battery cause your wifi to do this even though you are plugged into the outlet?

    Thanks, Dean. (PS OP feel free to email me if you want / can)

  7. sanjay vyas

    thanks
    really helpful
    sanjayvyas

  8. Syndulum

    not sure if you installed the hard drive in a correct manner. Just to be sure about it, you can access the bios (normally F2 or f10 key while restarting) by hitting the bios key during Power on Self Test. If the hard drive is not showing in the list of drives, you probably have either connected the wires wrong or may be your HD is dead. Besides, you can also look for the green light near the keyboard that has the pic of a HD. If that is not lit or not flickering, there is something wrong either with Hd or the way it is connected.

  9. prashanth

    my acer laptop mouse is not working kindly guide me

  10. I have a problem with my laptop Sony Vaio VGN CR353 series..
    After my mom fill some water on top of it my laptop won’t start normally with nothing respond at all from the led, the fan and etc…

    i found this great website and i follow all the basic repair and after i clening up the motherboard with alcohol and tootbrush like you said :D and finally i’ve progress my laptop begin to show some reaction..

    If you don’t mind please look up my short video that shows the recent condition og my laptop in

    http://www.youtube.com/watch?v=Wi5x3UXvdkg&feature=youtu.be

    hopefully you can give me any clue from your experience in laptop repairing.. maybe you’ve already faces the same problem :D

    Big apologize for my bad english :D
    Big thanks for any responds :D
    keep up the good work *two thumbs up

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