Today I spent some hours trying to figure out why I was not able use the wireless radio (WLAN) on an old Lenovo SL400 laptop.
When I tried to search for wireless networks, the machine told me to "Turn the wireless radio on". I tried to do that by disabling and enabling the wireless device, but the led for wireless connection just blinked for some seconds. Also nothing happened when I pressed Fn+F5.
I updated everything possible with Lenovo's own updater software and tried to enable and disable the wireless network card from BIOS. But still nothing, I was not able to use wlan.
While clicking around the settings, I suddenly got a popup window with the notification "The internal wireless device is set to 'radio off' in BIOS setup or hardware switch".
Because I certainly had checked from BIOS that the wireless was in use, I made the conclusion that there really HAS to be an actual physical switch for the wireless radio usage.
Really, I had to google the "lenovo wireless switch" and with a help of some forum post, I was able to locate the switch, from bottom of the front panel, out of sight. Definitely not an easy place to spot a small black switch!
Oh boy, how I felt shamed! My colleagues told me that every Lenovo has always had a hardware wireless switch. But every model may have it in slightly different place.
Well, this was my first Lenovo, so how could I knew that?!