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My laptop is Lenovo T400, about 4 years old, and my OS is Ubuntu 12.04.

  • When I restart my Ubuntu, the internal wireless adaptor works fine and can find and connect to our wireless network.

  • Then if I lift and move the laptop a little, the internal wireless adaptor becomes not working, i.e. it doesn't find any wireless network nearby, and the wireless icon (below the screen and showing if wireless adaptor working) becomes off (lose green light).

  • Then if I restart Ubuntu, the internal wireless adaptor works again.

What are some solutions to my problem?

  1. I have suspected that some wire connecting the internal wireless adaptor might have become disconnected. But a few months ago, I opened my laptop, and didn't find wires that have loose ends, and I detached and reattached all the wires connecting to the wireless adaptor.

    Also if the problem is indeed because of some wires, will it then be possible that restarting OS will make the adaptor working again?

  2. Will a USB wireless adaptor help to solve my problem? Such as this one Edimax EW-7811Un Network adapter - Hi-Speed USB?

Thanks and regards!

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Why did you open your laptop a few months ago? And do you specifically remember one or more small round wires that connected to the wireless card? Are you sure they fully engaged and didn't get mushed when you reconnected them? If not, open it again and double-check them. You may only have to take out the screws on a plate covering the WiFi adapter. (Like the grey and black cables in this picture.) –  David Schwartz Jul 17 '13 at 7:50
    
Thanks, @DavidSchwartz! (1) "Why did you open your laptop a few months ago?" I have had the problem for more than a year. (2) I can't be sure if they are fully engaged. But why restarting OS will temporarily solve the problem? (3) Will a USB wireless adaptor (mentioned in my post) solve the problem? –  Tim Jul 17 '13 at 8:02
    
If you can't be sure if those cables are fully engaged, then you should reconnect them. A USB wireless adapter will probably solve your problem. A new internal WiFi adapter probably will too. But if the problem is loose cables, just reconnecting them carefully (perhaps uncrushing them if they are crushed) likely will. I'm not sure why restarting the OS temporarily solves the problem, but I would still suggest troubleshooting the problem the same way. –  David Schwartz Jul 17 '13 at 8:27
    
When you lose connection, does the wireless adapter still show as a device? In other words, are you losing the signal, or are you losing the device? –  ernie Jul 18 '13 at 22:46
    
@ernie: the internal wireless adapter is not detected by Ubuntu. –  Tim Jul 18 '13 at 23:29

1 Answer 1

As David Schwartz said, your problem is a loose hardware connection. What gives it away is that fact that once you pick it up, the connection to the card is lost. You will need to clean all of the connections to and from the wireless card on both ends. This should fix your problem. If it doesn't then it could be a hardware failure or a drivers failure...or both.

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Thanks! But why restarting Ubuntu will make the adaptor work again? –  Tim Jul 17 '13 at 16:46
    
It could be temporarily tricking the system that there is a decent connection. Unfortunately, the only way to find out is to trouble shoot both the hardware and the software. I personally would start with the hardware which is much less complex. But if troubleshooting the hardware doesn't work, then troubleshooting the software is the only remaining option...which would mean having to dig through the internet for pre-made drivers or start building your own. –  halligan26 Jul 17 '13 at 16:51
    
Thanks! Restarting OS isn't tricking Ubuntu to think it works. It does work until I move my laptop. –  Tim Jul 17 '13 at 18:13

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