Kevinr
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Help for a new Pi user

Sat Aug 11, 2012 9:10 am

I have had my Pi for just over a week now but have not had much time to play with it yet, I have got everything going using Raspbian “wheezy” but have stumbled already. I can't seem to get access to the internet through the LAN, when I have the cable connected to the LAN all the lights come on but I still have no access to the net, I have checked out the cable and connection with other computers and all is working fine. The LAN lights on the Pi stay constantly on - no flashing, I would expect to see some flashing of these lights as it access the net. I would have thought that Raspbian “wheezy” would have been set up to have access to the net or do I need to do something to get it going? I'm thinking that I may have a dud Pi on my hands.

Any help appreciated.

Thanks Kevin

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alexeames
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Re: Help for a new Pi user

Sat Aug 11, 2012 11:56 am

How are you trying to access the internet? Are you in the GUI using a browser?
If you are, try going to the command line and test from there.

Go to command line prompt and type

Code: Select all

sudo apt-get update
If you have no internet access this process will fail.
If you have internet access it will update your package lists (without installing anything).

Let us know how it goes from there and someone will be able to chip in with further help depending on the outcome of this test.
Alex Eames RasPi.TV, RasP.iO

Kevinr
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Re: Help for a new Pi user

Sat Aug 11, 2012 12:47 pm

Thanks for the reply alexeames, yes I was trying with a browser from the GUI with no success and yes I have tried the exact command that you have suggested from the command line and yes it has failed on several occasions. I'm still leaning towards a faulty board.

Kevin.

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alexeames
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Re: Help for a new Pi user

Sat Aug 11, 2012 4:59 pm

Kevinr wrote:Thanks for the reply alexeames, yes I was trying with a browser from the GUI with no success and yes I have tried the exact command that you have suggested from the command line and yes it has failed on several occasions. I'm still leaning towards a faulty board.

Kevin.
It looks like it - unless you've got some strange setup on your router, such as mac address filtering or some such (which I wouldn't have thought was of much value with an ethernet connection). Unless it's your router settings, I'd be inclined to agree with you about the faulty board. Is there any way you can test it somewhere else on a different internet connection just to be sure?
Alex Eames RasPi.TV, RasP.iO

vinntec
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Re: Help for a new Pi user

Sat Aug 11, 2012 6:35 pm

Kevin - I don't think you said what is connected to the USB port(s)? In some cases these can cause the network connection to stop working. This is especially true if anything that needs to draw power FROM the RPi - eg. wireless keyboard/mouse or which might be putting power INTO the RPi - eg. powered hub.

If you have anything but totally DUMB keyboard and mouse connected to the USB ports it is worth trying. Power off the RPi off, disconnect all the USB, fire the Rpi up again and see if the network light blinks now. Give it a go and report back. If it works, tell us what was connected on USB and we can take it from there.

Peter

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tvinzant
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Re: Help for a new Pi user

Sat Aug 11, 2012 6:54 pm

From your Router config / admin screen do you see your Raspberry Pi?

From a command line on your Raspberry Pi can you PING http://www.yahoo.com?

A helpful video to watch.
http://www.youtube.com/watch?v=sSg2fShC3y0&feature=plcp

Kevinr
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Re: Help for a new Pi user

Sun Aug 12, 2012 2:21 am

Hi vinntec / Peter,

Thanks for your reply, you hit the nail on the head. I am using a normal USB keyboard and mouse but through a powered USB hub and I had noticed that the powered hub was also powering the Pi when I disconnected the mini USB power supply but thought nothing more of this until you came up with it, so I have taken the powered hub out and just connected the keyboard and mouse directly to the Pi and all is working now. Thanks for the help, now all I need to know is how do people manage to use a powered USB hub with their Pi and not cause this problem?

Thanks again

Kevin

vinntec
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Re: Help for a new Pi user

Sun Aug 12, 2012 6:05 am

Kevinr wrote:Hi vinntec / Peter,
...all I need to know is how do people manage to use a powered USB hub with their Pi and not cause this problem?
Hi Kevin - glad to be of use. My powered hub is also sat here twiddling its thumbs for the same reason as you. It is an official "bug" see http://elinux.org/RPi_Bugs as apparently is caused by the hub sending power up the cable to power attached devices which might be a good thing except that the RPi has a 100mA limiting fuse in the way (which resets itself eventually).

The way around it [currently] is to cut some of the wires in the USB cable from the powered hub which is described in the link above. Somewhere or the other there is also record of an agreed software bug in the USB driver which stops known good USB devices from working, so I am waiting for the outcome of this before resorting to wire cutting.

Peter

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Re: Help for a new Pi user

Sun Aug 12, 2012 10:12 am

Another solution is to power the Pi from a spare port on the hub so that powering on the hub also powers on the Pi. This avoids the back-power issue.

vinntec
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Re: Help for a new Pi user

Sun Aug 12, 2012 11:18 am

itimpi wrote:Another solution is to power the Pi from a spare port on the hub so that powering on the hub also powers on the Pi. This avoids the back-power issue.
Correct me if I am wrong... If I use a spare port and connect it to the power-input with an appropriate adapter then that is fine, but I cannot use it for data. So I need to connect another cable to a USB port on the RPi - which might still put 5V on one of the pins - or have I missed something somewhere?
Peter

oif
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Re: Help for a new Pi user

Sun Aug 12, 2012 12:02 pm

had the same problem. my pi didn't get an ip from dhcp. no clue why. so i configured it manually using the "interfaces" file in the network folder. after that my pi had acces to the www

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Re: Help for a new Pi user

Sun Aug 12, 2012 12:06 pm

vinntec wrote:
itimpi wrote:Another solution is to power the Pi from a spare port on the hub so that powering on the hub also powers on the Pi. This avoids the back-power issue.
Correct me if I am wrong... If I use a spare port and connect it to the power-input with an appropriate adapter then that is fine, but I cannot use it for data. So I need to connect another cable to a USB port on the RPi - which might still put 5V on one of the pins - or have I missed something somewhere?
Peter
That is correct. However if it is 5v from a common supply (the hub) and there is no scenario in which 5v is present on the Pi data USB port and not the Pi micro-USB power port (so that you are trying to back-power the Pi) then it all works OK.

vinntec
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Re: Help for a new Pi user

Sun Aug 12, 2012 12:49 pm

itimpi wrote: That is correct. However if it is 5v from a common supply (the hub) and there is no scenario in which 5v is present on the Pi data USB port and not the Pi micro-USB power port (so that you are trying to back-power the Pi) then it all works OK.
OK - I'll go and get an adapter and give it a try! I have a permanent 2A 5V supply always connected to the RPi but still had trouble with the powered hub connected on a USB port. I still can't see how this will work, but it must be to do with current rather than voltage (as both hub and RPi will still put 5V supply on the data USB port?. Oh my aching head! Peter

Kevinr
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Re: Help for a new Pi user

Sun Aug 12, 2012 12:56 pm

Hi again vinntec / Peter,

I guess that cutting power wires in the cable would fix the problem but what I may do is pull the USB hub apart and see if I can fit a diode into the power feed that is going back to the Pi from the powered hub that way power can still be feed from the Pi to the hub but not back the other way (only problem will be the .4 voltage drop across the diode reducing the power to about 4.5 volts going into the hub). I don't like cutting cables, makes them useless for other applications.

itimpi,

Tried all kinds of combinations of what you suggested and none of them worked, still had the freeze up of the LAN.

Thanks to everyone that came forward with suggestions and I will let you know how I get on with my plan with the diode.

Kevin

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