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Advice on Hardware Failures

Warranty Repair Non-warranty Repairs Guidance on Liquid Spills and Overheating
Diagnostics and Troubleshooting: Forums - Startup Problems - Input/Output Issues - Problems during Operation

1) If your Machine is still in Warranty

If you have a hardware issue with your computer while it is still under warranty, you must have it repaired by an authorised warranty repairer, otherwise the warranty may be invalidated. For failures within the first month of ownership, it is worth contacting the place you bought it from. Most will replace faulty equipment within the first 14 to 30 days after purchase.

After this initial period you will need to contact the manufacturer, and find the details of a local warranty repairer for that make. The easiest way to do this is via the manufacturers website. There may be a local warranty repairer but be prepared that you may need to send your computer away. The University of Oxford offers a warranty repair service for Apple hardware.

Warranty repair – what is covered and by who?

The majority of laptop warranties will cover hardware faults such as defective keyboards, monitor problems, motherboard or other issues with internal components. The laptop warranty generally covers the parts and labour for repairs.

A laptop warranty will also spell out the actions on your part which will void the warranty. For instance, accidental damage such as liquid spillage or dropping a machine is not covered by warranty. In fact, accidental damage will invalidate all warranty claims until the damage is put right by a certified warranty repairer at your cost. Even something as simple as opening the case and breaking a seal can be enough to void a warranty.

Damage to or loss of data is not covered by a laptop warranty. A laptop warranty will also state quite clearly that any problems associated with software – whether bundled or installed by you, will not be covered under warranty.

2) If your Machine is out of Warranty

The University of Oxford does not have a preferred PC repair company, so this would need to be sourced by yourself. Before you book it in somewhere, here are a few things to consider:

  • Word of mouth - do you know anyone who has already used them? Are they recommended? Can you find any good reviews?
  • Do they have a scale of charges in their information? Will they give you a quote?
  • It may also be worth getting more than one quote for the repair.
  • It is a good idea to photograph your hardware before you hand it in. A quick snap on your phone can be useful if it comes back with new dents or scratches.

The University of Oxford does offer an out of warranty repair service for Apple hardware.

Repair or replace?

The average lifespan of a laptop is approximately 4 years. With older machines, it is worth considering whether it is economically viable to have it repaired, or whether it would be better to replace it.

A major consideration will be the cost, both of the repair and of replacing the machine. See What are you paying for? below for a rough repair price guide.  It is also worth considering that, just as with old cars, it may be affordable to repair the current fault, but another one may appear soon on an older machine. In general major components such as screen and motherboard replacement are only worth carrying out on high-end equipment, while memory upgrades and hard disk replacement are reasonable value for money. If you do opt for a repair, consider also signing the machine up with the Computer Hardware Breakdown Service, which will cover future repairs on an out of warranty machine.

Online forums (see our forum section) are a good source of information about repairs (note that these sites are not affiliated to the University though).

What are you paying for?

The charge for a hardware repair consists of labour and parts.  Many repair services will take an up front, non-refundable diagnostic charge ranging from around £30 to £90. This will typically be deducted from the total repair bill if you go ahead with the work. Prices can vary quite a bit depending on the make and model of your machine and thus the cost of parts. Also bear in mind that some low price parts are not easy to change and will thus incur a higher labour charge (eg power input/other sockets). 

This local Which? page can give you a rough idea of typical repair prices.

3) General Guidance on two Common Laptop Issues

Liquid damage

Spilling any sort of liquid on your laptop, regardless of the quantity, can have fatal consequences for the machine. The most important step to minimising the damage is to switch the laptop off immediately  and let it dry out thoroughly following the steps below before powering it up again.

The extent of the damage will depend on how far inside the machine the liquid has seeped, and what it has actually come into contact with. Remember that liquid and electrical equipment don’t mix. 
To properly assess the damage, the machine should be examined by a hardware repair specialist. The cost of the repair, if it can be repaired, will depend upon what has been damaged.

  1. If the laptop is off at the time of the spill - do not turn it on!
  2. If it is on - turn the laptop off immediately
  3. Turn it upside down straight away - this should stops the liquid going deeper into the laptop
  4. Ensure the AC adapter and battery have been removed
  5. Unplug all peripherals (mice, wireless cards etc)
  6. Examine the keyboard and pour out the liquid contained in the keyboard enclosure
  7. Clean the spilled liquid - use a lint free paper towel or cloth to clean
  8. Clean any sticky residue with a damp cloth (especially if the liquid spilled was not water)
  9. Let everything dry, putting it in a warm dry room (i.e. airing cupboard) for 48 - 72 hours.
  10. Try turning the machine on. Bear in mind that even if the machine starts up, it may fail in future due to corrosion.


Overheating results when  a machine's cooling system is inadequate.


  • Laptop is too hot for your lap
  • Cooling fans running fast and noisy
  • Laptop struggles to perform basic tasks
  • Pixelated lines across the screen
  • Crashing and powering off

This can be caused by dust blocking the vents, an overused fan, or degenerated thermal compound (this is a sticky paste applied to the processing unit to maximise the direct heat transfer between the chip and the heat sink). Overheating is a serious fault that should be rectified quickly because the excess heat can damage internal components. Here are some tips that can help to keep your laptop cool:

  • Fix Internal Cooling - clean the fans that provide cooling to the CPU and graphics card. This is generally best done by  a hardware repair specialist and should only be undertaken yourself if your laptop is easy to open. Always ensure the laptop is shut down without any battery or power adapter connected and avoid using compressed air dusters as they risk distributing the dust over internal components and potentially damaging them.
  • Always keep laptop on a hard flat surface when using it. Most laptops suck in cooling air through their bottoms. If the laptop sits on an uneven surface like a blanket, pillow, or your lap, the flow of air into the laptop is disturbed. Subsequently, the cooling is not optimal, heat builds up, the surface becomes hot, the temperature of sucked in cooling air increases, and eventually the laptop overheats.
  • Invest in a laptop cooler - This provides additional cooling to your laptop. Before you purchase one, you need to understand the flow of air into and out of your laptop to ensure you buy the correct one. More information on laptop coolers.

If your machine is still overheating after this, then it is advised that you have it checked by a hardware repair specialist before the excess heat damages internal components 

4) Hardware diagnostics & troubleshooting

Useful Forums

With most faults/failures you probably aren’t the first person to experience it. With that being said, the best place to find out more about a fault is using some of the online forums available.

Startup Problems

a) The machine won’t boot

b) The machine makes a weird beeping noise when turned on

When you turn the computer on, it performs a Power On System Test (POST), during which it checks and initializes the system’s internal components.
If a serious error occurs, the computer does not display a message but emits a series of long and short beeps .
These codes are built into the Basic Input/Output System (BIOS) of the PC.
There is a web page you can use to check what your beep code means.

c) The machine starts and boots but doesn’t allow a log in

  • If you cannot log into your profile, it could be due to a corrupted profile or hard disc sector. For Windows machines you can use the recovery console. Depending on your version of Windows you can access the recovery console like so:
  • Mac OSX also has a recovery facility called macOS Recovery. Not all faults can be resolved with this tool, so it is also worth checking these further Mac troubleshooting tips.

Input/Output Issues

d) The keyboard isn’t working

  • If the keys are generally working but do not all produce the correct character, it is worth checking  if the language is set correctly or if the Num Lock key is on.
  • If you have a touch screen there is an option to use an on-screen keyboard. This can be found by going to the Start Menu, Control Panel then Ease of Access.
  • You can also use an external keyboard, either wired or wireless, and connect it to your device via a USB port.

e) The onboard speakers aren’t working

  • Firstly check that the audio driver is up to date. If you have the latest driver you can test the speaker by going to Control Panel and then Sound. Select the speakers and then choose properties. From the new Window select Advanced and then Test.
  • If you can hear audio through the headphones but not through the speakers this can indicate that the sensing circuitry in the headphone socket (port where the headphone cable is plugged in) has failed. When this fails, Windows "thinks" that a plug is in the headphone socket and so will not allow the audio signal to be switched to the speakers. You can try removing any dirt or dust from the headphone socket, however if this does not work then the solution is to replace the headphone socket. On some models the headphone socket is part of the motherboard making a replacement quite expensive. A workaround would be to use an external speaker system or headphones.

f) The machine powers up but the screen doesn't display anything

This could be an issue with the backlight, with a build-up of static electricity, or it could be a display failure.

  • If you can see something but is very faint then it is likely to be a backlight issue. This is usually not too expensive to repair backlight problms.
  • If you cannot see anything and the screen is completely black, the display connection or screen itself has failed. The connector is a fairly inexpensive repair but replacing the display screen can be costly. In the latter case an external monitor can be a more economic solution.
  • Sometimes screen malfunctions can be caused by static electricity which you need to drain. To do this without harming your machine you need to do the following:
    • Remove power cables and battery
    • Press the power button repeatedly for 15-30 seconds.
    • Connect the battery and/or power cable
    • Restart the machine

g) One or more USB ports aren't working

  • If it is just one port not working and all the others are OK, you can purchase a USB hub. You can plug this into a working port to give you additional USB sockets.
  • Sometimes the USB ports can spring back into action after using the Device Manager to check for hardware changes or to uninstall/reinstall the USB controller. This Microsoft article provides instructions.

h) The machine doesn't connect to WiFi 

If you are unable connect to any network but other devices can, then the fault is likely be with your machine. Check your network adapter drivers. If the software is up to date, disable and re-enable the driver. If this does not fix the issue, try using an external USB WiFi adapter/dongle as a workaround. If the external adapter works, then the fault is with the on board card, which would need to be replaced. Unfortunately this repair is very costly, so in most cases the dongle is a better option.

Problems during Operation

i) The machine displays an error message

Error codes help to identify the root cause of the fault and possible solutions. With any error code it is best to check it online. Simply type the error code into a search engine. Or this is a particularly useful page for Windows system error codes

j) Suspected viruses/malware

Indicators that a machine has a virus infection are quite varied, from unexpected pop-ups and strange browser behaviour to slow performance and unfamiliar virus warnings. All staff and students have access to SOPHOS antivirus software. This can be downloaded from our self-registration page. Use the software to perform a full scan and quarantine any threats it finds.
Another handy tools is MalwareBytes which is available as a free download. As with SOPHOS, perform a full scan and quarantine the items.

k) The time and date are wrong

This is a typical symptom that the CMOS ( Complimentry Metal Oxide Semi-conductor) battery has failed. The CMOS is a small amount of random access memory used to store the BIOS (Basic Input/Output System) settings when a machine is powered off. This means that a CMOS battery failure can also lead to booting problems and driver issues. Replacing the battery is a quick and easy job for a hardware repair specialist.

l) Why is Windows Update important?

The Windows Update (or Microsoft Update) utility is used to keep your Windows based computer up to date with the latest patches. Windows updates protect your systems from malicious software, resolve general windows issues and bugs and gives you access to new Windows features. It is recommended that you set these updates to automatic. To do this go to Control Panel and then Windows update. From there you can select Change settings and then select Install updates automatically.

Written by IT Services. Latest revision 1 November 2017