'invalid password' for airport extreme

[Tacoma]

I have two MacBook Pros connected to a home wifi network running from an Airport Extreme. One of the Macbook Pros is running fine, connected to the web and so on. The other has been running fine for months, but suddenly now it has gone off the home wifi network and can't get back on - when I try to sign it back in it says, 'Invalid Password". I know I'm using the right password, it's remembered on my keychain, I have it written down separately and I've tried inputting it automatically and manually many times. Anyone have experience or suggestions with this?
John

 

[jenzjen]

To double check your password, go onto your other Mac, delete the wireless network and try re-adding it. If you get the error again, your password is wrong, and from there I would completely factory reset the Airport (Google it) and repair both Macs to the new network name (I would not name it the same as the one I just reset).

 

[Tacoma]

if it doesn't work, switch it off and then switch it back on

I actually did manage to solve this quite simply, by going down to the basement, switching off the Airport Extreme and then switching it on again. That seemed to be enough that both computers came back onto the network without me having to do anything. Thanks for taking the trouble to reply, jenzjen, I do truly appreciate it, however I'm actually quite glad I did not take your advice - given that something was going wrong with the system, not with my knowledge of the password, God knows how many hours I would have spent in a maze of reset passwords and failed attempts to log in.

I had forgotten the most basic rule, if it doesn't work, switch it off and then switch it back on.

 

[jenzjen]

Right, most assume people have at least tried the power down trick before posting. Glad it works now.

 

[Nobita]

Sorry for bringing this up again, I have experienced this a few times where my iPhone & Mac can connect but not my iPad (and sometimes the other way around).

I can reset it every time, but it happens like once a month. Anyone knows why it happens?

 

[GuitarG20]

Not sure if this is related but-

On my college campus they have blanket Wi-fi. It works almost all the time, but if I move far enough, I have to remember to go back into my iPhone and renew my lease. Apparently, when I move off the router I was using, I need to get a new IP and my iPhone tries to use the one it already had, which obviously doesn't work since the new router doesn't recognize it.