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micksulley
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Ethernet Fails on my Rev 2 Pi

Thu Jul 11, 2013 7:10 pm

Hi,

I have a problem with a rev 2 Pi (my rev1 seems fine in this respect). I have created a new SD card with latest Raspian (tried both via NOOB and standard burn). I run the initial setup for locale, time, etc then reboot.
The Pi is connected via a cable into my router, cable tested with other machines. I can now ping my router and other machines on my network. I have a keyboard via USB but nothing else, voltage checked at 4.95 so thats OK. I then run
apt-get update
It starts off as normal but hangs on the line ending 'Waiting for headers'.
If I Ctrl C to kill this and try ping I cannot connect to anything, so it seems that it is hanging because the network connection has disappeared. If I unplug the cable and plug it into something else that works fine, so the cable connection is still OK.
Why does the Pi loose its connection?

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Re: Ethernet Fails on Rev 2 Pi

Thu Jul 11, 2013 7:19 pm

I find that, on occasion, the interface goes down. If you have keyboard and monitor connected to your Pi, try:

ifup eth0
or
ifup -a

You can check "man ifup", you can see if you need any other flags for your situation.

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Davespice
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Re: Ethernet Fails on Rev 2 Pi

Thu Jul 11, 2013 7:49 pm

Okay so let's see if we can verify that it is losing the connection or not.
First reboot, log in as normal. Press Alt-F2 and log in again. And use this command;

Code: Select all

watch -n 2 ifconfig
Now press Alt-F1 to go back to the original login, run sudo apt-get update and immediately press Alt-F2 to go back to the second login.
Watch the line that says inet addr under eth0. If this line suddenly disappears then you do indeed have a problem.

When I run apt-get update it does take a bit of time to complete, so I wonder if you're just being a little impatient with it?
The above test though will tell you for sure, you can also look for the link lights on the Pi and on your router to see if the connection is dropping.
If eth0 does not lose its inet addr, then the connection is actually still up.

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micksulley
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Re: Ethernet Fails on Rev 2 Pi

Thu Jul 11, 2013 7:54 pm

OK rebooted, ifup returns
ifup: interface eth0 already configured
If I run apt-get update it gets stuck
Ctrl C to kill it and try ifup again, it still returns
ifup: interface eth0 already configured
so it thinks that it is running, but I cannot ping anything.

What causes this?

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Davespice
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Re: Ethernet Fails on Rev 2 Pi

Thu Jul 11, 2013 7:57 pm

Please can you do the test I posted above?

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micksulley
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Re: Ethernet Fails on Rev 2 Pi

Thu Jul 11, 2013 8:03 pm

Hi Davespice,
OK I did that, that line does not disappear, but the RX packets line the error number just keeps increasing.

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Re: Ethernet Fails on Rev 2 Pi

Thu Jul 11, 2013 8:08 pm

Oh the RX error packets are increasing... ah. That's almost as if its recieving garbage...
I wonder... can you try it on a different port on the router and see if that make any difference?

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micksulley
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Re: Ethernet Fails on Rev 2 Pi

Thu Jul 11, 2013 8:15 pm

This router is actually just used as a switch, and I have tried a different port with no difference. I can try plugging it into the main router, just need to relocate everything upstairs.......
I'll be back......

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micksulley
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Re: Ethernet Fails on Rev 2 Pi

Thu Jul 11, 2013 8:41 pm

OK tried that and I get the same thing.

I also tried the same test on my rev 1 Pi, back in the original position using the same cables and ports and that works fine, no errors.

Could it be that my rev 2 Pi is faulty?

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Davespice
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Re: Ethernet Fails on Rev 2 Pi

Thu Jul 11, 2013 9:18 pm

That does sound like something is very wrong. Try an update from within raspi-config, which will give you all the very latest firmware, and failing that I don't really know what to suggest.

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Re: Ethernet Fails on Rev 2 Pi

Thu Jul 11, 2013 9:35 pm

One other idea... can you tell me the CPU temp? Is the Pi inside a case?

Code: Select all

/opt/vc/bin/vcgencmd measure_temp

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micksulley
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Re: Ethernet Fails on Rev 2 Pi

Thu Jul 11, 2013 9:40 pm

That freezes as well. I tried running watch ifconfig at the same time and I just see loads off errors again.

My daughter has a rev 2 Pi as well, so I will see if she can bring that over. I assume that this is not a problem that everyone has, so I should be able to swap SD cards to prove if it is a Pi or an SD problem.

May take a few days to organise but I will let you know what happens.

Thanks for your help anyway.
Mick

It is not in a box and temp is 40.1 C. Doesn't sound that hot to me

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Re: Ethernet Fails on Rev 2 Pi

Fri Jul 12, 2013 8:18 am

micksulley wrote:I assume that this is not a problem that everyone has, so I should be able to swap SD cards to prove if it is a Pi or an SD problem.
Correct. That will be good test, please report the outcome of this as I am interested to know.
If it looks like it might be an SD card issue, check against this list; http://elinux.org/RPi_SD_cards#Working_ ... g_SD_cards
micksulley wrote:It is not in a box and temp is 40.1 C. Doesn't sound that hot to me
That's fine. The CPU is rated up to 85 C.

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micksulley
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Re: Ethernet Fails on Rev 2 Pi

Fri Jul 12, 2013 2:11 pm

I borrowed my daughters Pi for tests, here are the results -
Comparison
Charlotte's Made in China
Mine Made in UK
Charlotte's Processor SKhynix
Mine Processor Samsung
they seem the same in all other respects

SD cards
Charlotte's unknown 4 Gb
Mine QUMOX 32 Gb

Charlotte's Pi has Raspian installed but had never been connected to the internet, so no updates have been run on her SD, so in those terms should be in the same state as mine.

Test - open two sessions one to watch ifconfig, the other to run apt-get update

First test - repeat with my Pi & my SD to be sure
eth0 RX packets - errors keep increasing

Second test - repeat with Charlotte's Pi and my SD
it works!! No errors at all

Third test - repeat with my Pi and Charlotte's SD
eth0 RX packets - errors keep increasing

Fourth test - repeat with Charlotte's Pi and Charlotte's SD
it works - as I would expect

Fifth test - repeat with my Pi and my SD - my SD was updated in Charlotte's Pi earlier
it works - no errors, but...
run sudo apt-get upgrade and the eth0 RX packets errors start increasing again.

I believe that this proves that my Pi is faulty.

Thanks to Davespice for your help and for teaching me a couple more bits of Linux that I didn't know :D

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Re: Ethernet Fails on Rev 2 Pi

Fri Jul 12, 2013 2:55 pm

Okay right, before you send it back do you want to try the hair dryer trick? :D
If it's a reflux issue heating it up with a hair dryer can sometimes cause a hairline crack somewhere to reconnect and fix an issue.
Don't really nuke it or you'll melt stuff and then it really will be dead and you won't be able to replace it.

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