I have a Raspberry Pi. model B, flashed with Raspbian 2014-06-20, Microsoft Wired Keyboard 600 & Edimax EW-7811Un 150M 11n Wi-Fi USB Adapter... Everything was working fine, even I created an Android application to control the PI via WIFI.

Suddenly, I am experiencing some problems... 1) When connecting Ethernet or WIFI with the Keyboard, the keyboard gets frozen and does not work anymore.

2) WIFI seems not to work anymore (I don't see the blue flashing light that indicates that is working, I see it when connecting the dongle in my Laptop)

3) Ethernet seems not to work anymore. ping raspberrypi.local -> cannot resolve raspberrypi.local: Unknown host ssh raspberrypi.local -l pi -> ssh: Could not resolve hostname raspberrypi.local: nodename nor servname provided, or not known

as I can't not have connected Ethernet & Keyboard I can't follow up what's going on, with ipconfig or so on...Anyway I've checked all the config files are OK, but I don't see that PI is getting any IP from the router...

I changed the Ethernet cable as well, even I've bought another PI, woth the same result, flashing another SD Card...

I even put my PI in the fridge for 2 hours :-)

Everything is quite surreal

  • Is it the same regardless of what USB port you plug the wifi dongle into? What happens if you used an external powered USB-hub?
    – Bex
    Commented Aug 13, 2014 at 19:43
  • First thing to check is that your power supply is powerful enough. Use a meter to check the voltage if you can. Sometimes the specs printed on the supply are not accurate.
    – Craig
    Commented Aug 13, 2014 at 19:47
  • 1
    mmm...I think you are true, my PI power supply just broken, I that's the only think I changed, I will go to buy another one tomorrow and I will tell you about
    – darkZone
    Commented Aug 13, 2014 at 20:00

1 Answer 1


as Craig said, the problem was in the power supply, that was supposed to give me around 1000mA, but only gives me around 800mA...

800mA. it's ok for 1 USB connection + screen
1000mA. it's fine with 1 USB connection + screen + Ethernet
for 2 USB connections + screen + Ethernet you will need around 1200mA. ( I guess)

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