Troubleshooting your PC

Cannot connect a Bluetooth device

There are a number of reasons why you may not be able to connect to a Bluetooth device, such as a phone or headset.

Connection blocked or untrusted

Some Bluetooth devices block connections by default, or require you to change a setting to allow connections to be made. Make sure that your device is set up to allow connections.

Bluetooth hardware not recognized

Your Bluetooth adapter or dongle may not have been recognized by the computer. This could be because drivers for the adapter are not installed. Some Bluetooth adapters are not supported on Linux, so you may not be able to get the right drivers for them. In this case, you will probably have to get a different Bluetooth adapter.

Adapter is not switched on

Make sure that your Bluetooth adapter is switched on. Open the Bluetooth panel and check that it is not disabled

Device Bluetooth connection switched off

Check that Bluetooth is turned on on the device you are trying to connect to, and that it is discoverable or visible. For example, if you are trying to connect to a phone, make sure that it is not in airplane mode.

No Bluetooth adapter in your computer

Many computers do not have Bluetooth adapters. You can buy an adapter if you want to use Bluetooth.

Power Problems

My computer gets really hot

Most computers get warm after a while, and some can get quite hot. This is normal: it is simply part of the way that the computer cools itself. However, if your computer gets very warm it could be a sign that it is overheating, which can potentially cause damage.

Most laptops get reasonably warm once you have been using them for a while. It is generally nothing to worry about — computers produce a lot of heat and laptops are very compact, so they need to remove their heat rapidly and their outer casing warms up as a result. Some laptops do get too hot, however, and may be uncomfortable to use. This is normally the result of a poorly-designed cooling system. You can sometimes get additional cooling accessories which fit to the bottom of the laptop and provide more efficient cooling.

If you have a desktop computer which feels hot to the touch, it may have insufficient cooling. If this concerns you, you can buy extra cooling fans or check that the cooling fans and vents are free from dust and other blockages. You might want to consider putting the computer in a better-ventilated area too — if kept in confined spaces (for example, in a cupboard), the cooling system in the computer may not be able to remove heat and circulate cool air fast enough.

Some people are concerned about the health risks of using hot laptops. There are suggestions that prolonged use of a hot laptop on your lap might possibly reduce (male) fertility, and there are reports of minor burns being suffered too (in extreme cases). If you are concerned about these potential problems, you may wish to consult a medical practitioner for advice. Of course, you can simply choose not to rest the laptop on your lap.

Most modern computers will shut themselves down if they get too hot, to prevent themselves from becoming damaged. If your computer keeps shutting down, this might be the reason. If your computer is overheating, you will probably need to get it repaired.

The laptop fan is always running

If cooling fan in your laptop is always running, it could be that the hardware that controls the cooling system in the laptop is not very well supported in Linux. Some laptops need extra software to control their cooling fans efficiently, but this software may not be installed (or available for Linux at all) and so the fans just run at full speed all of the time.

If this is the case, you may be able to change some settings or install extra software that allows full control of the fan. For example, vaiofand can be installed to control the fans of some Sony VAIO laptops. Installing this software is quite a technical process which is highly dependent on the make and model of your laptop, so you may wish to seek specific advice on how to do it for your computer.

It is also possible that your laptop just produces a lot of heat. This does not necessarily mean that it is overheating; it might just need the fan to run at full speed all of the time to allow it to stay cool enough. If this is the case, you have little option but to let the fan run at full speed all of the time. You can sometimes buy additional cooling accessories for your laptop which may help.

My computer will not turn on

There are a number of reasons why your computer will not turn on. This topic gives a brief overview of some of the possible reasons.

Computer not plugged in, empty battery, or loose cable

Make sure that the power cables of the computer are firmly plugged in and the power outlets are switched on. Make sure that the monitor is plugged in and switched on too. If you have a laptop, connect the charging cable (in case it has run out of battery). You may also want to check that the battery is correctly fitted in place (check the underside of the laptop) if it is removable.

Problem with the computer hardware

A component of your computer may be broken or malfunctioning. If this is the case, you will need to get your computer repaired. Common faults include a broken power supply unit, incorrectly-fitted components (such as the memory or RAM) and a faulty motherboard.

The computer beeps and then switches off

If the computer beeps several times when you turn it on and then turns off (or fails to start), it may be indicating that it has detected a problem. These beeps are sometimes referred to asbeep codes, and the pattern of beeps is intended to tell you what the problem with the computer is. Different manufacturers use different beep codes, so you will have to consult the manual for your computer’s motherboard, or take your computer in for repairs.

The computer fans are spinning but nothing is on the screen

The first thing to check is that your monitor is plugged in and turned on.

This problem could also be due to a hardware fault. The fans might turn on when you press the power button, but other essential parts of the computer might fail to turn on. In this case, take your computer in for repairs.

Why does my computer not turn back on after I suspended it?

If you suspend your computer, then try to resume it, you may find that it does not work as you expected. This could be because suspend is not supported properly by your hardware.

My computer is suspended and is not resuming

If you suspend your computer and then press a key or click the mouse, it should wake up and display a screen asking for your password. If this does not happen, try pressing the power button (do not hold it in, just press it once).

If this still does not help, make sure that your computer’s monitor is switched on and try pressing a key on the keyboard again.

As a last resort, turn off the computer by holding in the power button for 5-10 seconds, although you will lose any unsaved work by doing this. You should then be able to turn on the computer again.

If this happens every time you suspend your computer, the suspend feature may not work with your hardware.

If your computer loses power and does not have an alternative power supply (such as a working battery), it will switch off.

My wireless connection (or other hardware) does not work when I wake up my computer

If you suspend your computer and then resume it again, you may find that your internet connection, mouse, or some other device does not work properly. This could be because the driver for the device does not properly support suspend. This is a problem with the driver and not the device itself.

If the device has a power switch, try turning it off and then on again. In most cases, the device will start working again. If it connects via a USB cable or similar, unplug the device and then plug it in again and see if it works.

If you cannot turn off or unplug the device, or if this does not work, you may need to restart your computer for the device to start working again.

Will my computer work with a power supply in another country?

Different countries use power supplies at different voltages (usually 110V or 220-240V) and AC frequencies (usually 50 Hz or 60 Hz). Your computer should work with a power supply in a different country as long as you have an appropriate power adapter. You may also need to flip a switch.

If you have a laptop, all you should need to do is get the right plug for your power adapter. Some laptops come packaged with more than one plug for their adapter, so you may already have the right one. If not, plugging your existing one into a standard travel adapter will suffice.

If you have a desktop computer, you can also get a cable with a different plug, or use a travel adapter. In this case, however, you may need to change the voltage switch on the computer’s power supply, if there is one. Many computers do not have a switch like this, and will happily work with either voltage. Look at the back of the computer and find the socket that the power cable plugs into. Somewhere nearby, there may be a small switch marked “110V” or “230V” (for example). Switch it if you need to.

Troubleshoot wireless connection issues

This is a step-by-step troubleshooting guide to help you identify and fix wireless problems. If you cannot connect to a wireless network for some reason, try following the instructions here.

We will proceed through the following steps to get your computer connected to the internet:

  • Performing an initial check

  • Gathering information about your hardware

  • Checking your hardware

  • Attempting to create a connection to your wireless router

  • Performing a check of your modem and router

Perform an initial connection check

In this step you will check some basic information about your wireless network connection. This is to make sure that your networking problem isn’t caused by a relatively simple issue, like the wireless connection being turned off, and to prepare for the next few troubleshooting steps.

  1. Make sure that your laptop is not connected to a wired internet connection.

  2. If you have an external wireless adapter (such as a USB adapter, or a PCMCIA card that plugs into your laptop), make sure that it is firmly inserted into the proper slot on your computer.

  3. If your wireless card is inside your computer, make sure that the wireless switch is turned on (if it has one). Laptops often have wireless switches that you can toggle by pressing a combination of keyboard keys.

  4. Click the system status area on the top bar and selec tWi-Fi, then select Wi-Fi Settings. Make sure that Wi-Fi is set to ON. You should also check that Airplane Mode is not switched on.

  5. Open the Terminal, type nmcli device and press Enter.

    This will display information about your network interfaces and connection status. Look down the list of information and see if there is an item related to the wireless network adapter. If the state is connected, it means that the adapter is working and connected to your wireless router.

If you are connected to your wireless router, but you still cannot access the internet, your router may not be set up correctly, or your Internet Service Provider (ISP) may be experiencing some technical problems. Review your router and ISP setup guides to make sure the settings are correct, or contact your ISP for support.

If the information from nmcli device did not indicate that you were connected to the network, continue to proceed to the next portion of the troubleshooting guide.

Gather information about your network hardware

In this step, you will collect information about your wireless network device. The way you fix many wireless problems depends on the make and model number of the wireless adapter, so you will need to make a note of these details. It can also be helpful to have some of the items that came with your computer too, like device driver installation discs. Look for the following items, if you still have them:

  • The packaging and instructions for your wireless devices (especially the user guide for your router)

  • The disc containing drivers for your wireless adapter (even if it only contains Windows drivers)

  • The manufacturers and model numbers of your computer, wireless adapter and router. This information can usually be found on the underside or reverse of the device.

  • Any version or revision numbers that may be printed on your wireless network devices or their packaging. These can be especially helpful, so look carefully.

  • Anything on the driver disc that identifies either the device itself, its “firmware” version, or the components (chipset) it uses.

If possible, try to get access to an alternative working internet connection so that you can download software and drivers if necessary. (Plugging your computer directly into the router with an Ethernet network cable is one way of providing this, but only plug it in when you need to.)

Once you have as many of these items as possible, continue further.

Check that the wireless adapter was recognized

Even though the wireless adapter is connected to the computer, it may not have been recognized as a network device by the computer. In this step, you will check whether the device was recognized properly.

  1. Open a Terminal window, type lshw -C network and pressEnter. If this gives an error message, you may need to install the lshw program on your computer.

  2. Look through the information that appeared and find theWireless interfacesection. If your wireless adapter was detected properly, you should see something similar (but not identical) to this:

       	description: Wireless interface
       	product: PRO/Wireless 3945ABG [Golan] Network Connection
       	vendor: Intel Corporation
  3. If a wireless device is listed, continue on to the Device Drivers step.

    If a wireless device is not listed, the next steps you take will depend on the type of device that you use. Refer to the section below that is relevant to the type of wireless adapter that your computer has (internal PCI, USB, or PCMCIA).

PCI (internal) wireless adapter

Internal PCI adapters are the most common, and are found in most laptops made within the past few years. To check if your PCI wireless adapter was recognized:

  1. Open a Terminal, type lspci and press Enter.

  2. Look through the list of devices that is shown and find any that are marked Network controller or Ethernet controller. Several devices may be marked in this way; the one corresponding to your wireless adapter might include words like wireless, WLAN, wifi or 802.11. Here is an example of what the entry might look like:

    Network controller: Intel Corporation PRO/Wireless 3945ABG [Golan] Network Connection

  3. If you found your wireless adapter in the list, proceed to the Device Drivers step. If you didn’t find anything related to your wireless adapter, see the instructions below.

USB wireless adapter

Wireless adapters that plug into a USB port on your computer are less common. They can plug directly into a USB port, or may be connected by a USB cable. 3G/mobile broadband adapters look quite similar to wireless (wifi) adapters, so if you think you have a USB wireless adapter, double-check that it is not actually a 3G adapter. To check if your USB wireless adapter was recognized:

  1. Open a Terminal, type lsusb and press Enter.

  2. Look through the list of devices that is shown and find any that seem to refer to a wireless or network device. The one corresponding to your wireless adapter might include words like wireless, WLAN, wifi or 802.11. Here is an example of what the entry might look like:

    Bus 005 Device 009: ID 12d1:140b Huawei Technologies Co., Ltd. EC1260 Wireless Data Modem HSD USB Card

  3. If you found your wireless adapter in the list, proceed to the Device Drivers step. If you didn’t find anything related to your wireless adapter, see the instructions below.

Checking for a PCMCIA device

PCMCIA wireless adapters are typically rectangular cards which slot into the side of your laptop. They are more commonly found in older computers. To check if your PCMCIA adapter was recognized:

  1. Start your computer without the wireless adapter plugged in.

  2. Open a Terminal and type the following, then pressEnter:

    tail -f /var/log/messages

    This will display a list of messages related to your computer’s hardware, and will automatically update if anything to do with your hardware changes.

  3. Insert your wireless adapter into the PCMCIA slot and see what changes in the Terminal window. The changes should include some information about your wireless adapter. Look through them and see if you can identify it.

  4. To stop the command from running in the Terminal, press Ctrl+C. After you have done that, you can close the Terminal if you like.

  5. If you found any information about your wireless adapter, proceed to the Device Drivers step. If you didn’t find anything related to your wireless adapter, see the instructions below.

Wireless adapter was not recognized

If your wireless adapter was not recognized, it might not be working properly or the correct drivers may not be installed for it. Check to see if there are any drivers you can install.

To get specific help, look at the support options on your manufacturer's website. These might include mailing lists and web chats where you can ask about your wireless adapter, for example.

Make sure that working device drivers are installed

In this step you can check to see if you can get working device drivers for your wireless adapter. A device driver is a piece of software which tells the computer how to make a hardware device work properly. Even though the wireless adapter has been recognized by the computer, it may not have drivers which work very well. You may be able to find different drivers for the wireless adapter which do work. Try some of the options below:

  • Check to see if your wireless adapter is on a list of supported devices. BackSlash Linux supports all drivers supported by Ubuntu

  • Look for restricted (binary) drivers.

    Many Linux distributions only come with device drivers which are free and open source. This is because they cannot distribute drivers which are proprietary, or closed-source. If the correct driver for your wireless adapter is only available in a non-free, or “binary-only” version, it may not be installed by default. If this is the case, look on the wireless adapter manufacturer’s website to see if they have any Linux drivers.

    Some Linux distributions have a tool that can download restricted drivers for you. If your distribution has one of these, use it to see if it can find any wireless drivers for you.

  • Use the Windows drivers for your adapter.

    In general, you cannot use a device driver designed for one operating system (like Windows) on another operating system (like Linux). This is because they have different ways of handling devices. For wireless adapters, however, you can install a compatibility layer called NDISwrapper which lets you use some Windows wireless drivers on Linux. This is useful because wireless adapters almost always have Windows drivers available for them, whereas Linux drivers are sometimes not available. You can learn more about how to use NDISwrapper here. Note that not all wireless drivers can be used through NDISwrapper.

If none of these options work, you may want to try a different wireless adapter to see if you can get that working. USB wireless adapters are often quite cheap, and will plug into any computer. You should check that the adapter is compatible with your Linux distribution before buying it, though.

Sound Problems

I cannot hear any sounds on the computer

If you cannot hear any sounds on your computer, for example when you try to play music, go through the following troubleshooting tips.

Make sure that the sound is not muted

Open the sound menu and make sure that the sound is not muted or turned down.

Some laptops have mute switches or keys on their keyboards — try pressing that key to see if it unmutes the sound.

You should also check that you have not muted the application that you are using to play sound (for example, your music player or movie player). The application may have a mute or volume button in its main window, so check that.

Also, you can check the Applications tab in the Sound GUI:

  1. Open Settings.

  2. Click Sound.

  3. Go to the Applications tab and check that your application is not muted.

Check that the speakers are turned on and connected properly

If your computer has external speakers, make sure that they are turned on and that the volume is turned up. Make sure that the speaker cable is securely plugged into the “output” audio socket on your computer. This socket is usually light green in color.

Some sound cards can switch between the socket they use for output (to the speakers) and the socket for input (from a microphone, for instance). The output socket may be different when running Linux, Windows or Mac OS. Try connecting the speaker cable to a different audio socket on your computer.

A final thing to check is that the audio cable is securely plugged into the back of the speakers. Some speakers have more than one input, too.

Check that the correct sound device is selected

Some computers have multiple “sound devices” installed. Some of these are capable of outputting sound and some are not, so you should check that you have the correct sound device selected. This might involve some trial-and-error to choose the right one.

  1. Open Settings.

  2. Click on Sound to open the panel.

  3. In the Output tab, change the Profile settings for the selected device and play a sound to see if it works. You might need to go through the list and try each profile.

    If that does not work, you might want to try doing the same for any other devices that are listed.

Check that the sound card was detected properly

Your sound card may not have been detected properly probably because the drivers for the card are not installed. You may need to install the drivers for the card manually. How you do this depends on the type of the card.

Run the lspci command in the Terminal to find out what sound card you have:

  1. Open a Terminal.

  2. Run lspci as superuser; either type sudo lspci and type your password, or type su, enter the root(administrative) password, then type lspci.

  3. Check if an audio controller or audio device is listed: in such case you should see the make and model number of the sound card. Also,lspci -v shows a list with more detailed information.

You may be able to find and install drivers for your card. It is best to ask on support forums (or otherwise) for your manufacturer for instructions.

If you cannot get drivers for your sound card, you might prefer to buy a new sound card. You can get sound cards that can be installed inside the computer and external USB sound cards.

I hear crackling or buzzing when sounds are playing

If you hear crackling or buzzing when sounds are playing on your computer, you may have a problem with the audio cables or connectors, or a problem with the drivers for the sound card.

  • Check that the speakers are plugged in correctly.

    If the speakers are not fully plugged in, or if they are plugged into the wrong socket, you might hear a buzzing sound.

  • Make sure the speaker/headphone cable is not damaged.

    Audio cables and connectors can gradually wear with use. Try plugging the cable or headphones into another audio device (like an MP3 player or a CD player) to check if there is still a crackling sound. If there is, you may need to replace the cable or headphones.

  • Check if the sound drivers are not very good.

    Some sound cards do not work very well on Linux because they do not have very good drivers. This problem is more difficult to identify. Try searching for the make and model of your sound card on the internet, plus the search term “Linux”, to see if other people are having the same problem.

    You can use the lspci command to get more information about your sound card.

Screen and Graphics Problems

Why do things look fuzzy/pixelated on my screen?

This can happen because the display resolution that you have set it is not the right one for your screen.

To solve this, open Settings. Click on Displays to open the panel. Try some of the Resolution options and set the one that makes the screen look better.

When multiple displays are connected

If you have two displays connected to the computer (for example, a normal monitor and a projector), the displays might have different resolutions. However, the computer’s graphics card can only display the screen in one resolution at a time, so at least one of the displays might look fuzzy.

You can set it so that the two displays have different resolutions, but you will not be able to display the same thing on both screens simultaneously. In effect, you will have two independent screens connected at the same time. You can move windows from one screen to another, but you cannot show the same window on both screens at once.

To set up the displays so that they each have their own resolution:

  1. Open Settings.

  2. Click on Displays to open the panel.

  3. The displays should be listed as Mirrored. Select your main display.

  4. Select Primary in the list of display configurations, and then click Apply to save.

  5. Select each display in turn from the gray box at the top of the Displays window. Change the Resolution until that display looks right.