R-Pi Troubleshooting

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This page lists the most common problems and suggests some solutions.

Power / Start-up
A good power supply that will supply 5V is vital. There is more information about power supplies and troubleshooting.

Red power LED does not light, nothing on display
The power is not properly connected.

Red power LED is on, green LED does not flash, nothing on display
The Raspberry Pi cannot find a valid image on the SD card. Check that you have correctly written a Raspberry Pi image to the card. See also, Known SD Cards.

Raspberry Pi shuts down soon after booting up
This is caused by a power supply with too low voltage or too high voltage. Or it could be the cable. See: On_the_RPi_usb_power_cable

Keyboard randomly repeats key presses
This is caused by inadequate power. Use a good power supply and a good power cable. Some USB devices require a lot of power, most will have a label showing the voltage and mA requirements, they should be 5v 100mA each max, any more than this they must be used with a powered USB hub. Try unplugging every USB device except the keyboard (you should also note that some keyboards have built in hubs and can try to draw 1500mA (Pi can only handle 100mA per USB slot without a hub)).

General / Formatting
If you are having problems setting up your memory card you might want to try erasing it completely - especially if it has been used elsewhere and still contains data / partitions. Windows and Mac users can download a formatting tool from the SD Association: https://www.sdcard.org/downloads/formatter_3/ You can also put one of the distribution images on the card. That should wipe the partition table. Make sure you put the image on the whole disk, e.g. /dev/sdd, NOT /dev/sdd1 ! Afterwards you should be able to see a small boot partition with boot files like start.elf.

Ethernet connection is lost when a USB device is plugged in
This is caused by inadequate power. Use a good power supply and a good power cable. Some USB devices require a lot of power, so they must be used with a powered USB hub. Some cheap USB hubs suck power from the Raspberry Pi even if a USB power supply is connected.

Sound does not work
Device drivers for sound are still being developed. Please wait for the community to improve the situation.

Video does not play or plays very slowly
It must be H264 or XVID. Device drivers for video are still being developed. The XMBC distribution is the only distribution with good video support at the moment. Please wait for the community to improve the situation.

Can only get 800x480 resolution in LXDE (Arch linux)
Known issue with distro package as of 17-Apri-2012 - there's some missing boot config info. Creating a suitable cmdline.txt fixes it - type the following at the Raspberry Pi command line:

sudo echo "dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 root=/dev/mmcblk0p2 rootfstype=ext3 rootwait" >/boot/cmdline.txt

Interference visible on a HDMI or DVI monitor
This may be caused by loss of signal on long video cables. The signal level may be increased by changing a configuration parameter.

Enter the command sudo nano /boot/config.txt

If this file is empty or does not contain the config_hdmi_boost parameter, add the following line config_hdmi_boost=4

If this file already contains the config_hdmi_boost parameter, use the editor to change the value.

Use Ctrl-x to exit the editor. After exiting the editor, restart using the command sudo reboot

You may experiment with different values of config_hdmi_boost. Value 1 is used for very short cables, value 7 is used for very long cables. Note that you must use the correct reboot command to force a write of the edited file to the SD card.

GPIO
To be added.

Troubleshooting power problems
If you think you have a problem with your power supply, it is a good idea to check the actual voltage on the Raspberry Pi circuit board. Two test points labelled TP1 and TP2 are provided on the circuit board to facilitate voltage measurements.

Use a multimeter which is set to the range 20 volts DC (or 20v =). You should see a voltage between 4.75 and 5.25 volts. Anything outside this range indicates that you have a problem with your power supply or your power cable.

On the other hand, a multimeter displays the average voltage. If short power-burst-requirements on the 'pi are not adequately regulated by the power supply the Raspberry Pi might still have power problems even though the multimeter gives the OK.