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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?
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?
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!
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 – 2013-07-17T07:50:15.617Thanks, @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 – 2013-07-17T08:02:32.350
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 – 2013-07-17T08:27:07.830
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 – 2013-07-18T22:46:36.557
@ernie: the internal wireless adapter is not detected by Ubuntu. – Tim – 2013-07-18T23:29:55.710
That's really strange . . . the wires to the wireless card are the antenna, so if there was a loose connection there, you'd expect signal loss, not for the device to disappear. For the device to disappear, it'd have to be wiggling out of the slot it sits in. What do the logs show right after the card disappears? (dmesg output and /var/log/syslog would be good places to start) – ernie – 2013-07-19T16:23:56.427
@ernie: Thanks, I can't restart my OS to make the internal wireless adaptor to work again now. I will post the output of the command after I restart Ubuntu next time. – Tim – 2013-07-19T16:34:19.293