I have at least ten devices in the house, they can all connect to the wireless network with no problems but when i try to connect the macbook pro, it says i have an invalid password. I have replaced the router and re-connected all other devices, but again the macbook will not connect. I have connected via an ethernet cable and that is ok.
MacBook Pro, OS X Mavericks (10.9.5)
Distance is very important, and proximity to interference of 2.4 Ghz devices is too. Within 5 meters/15 feet, you may have overlapping radio waves causing issues with reception. Beyond 150 feet, older WiFi routers have trouble in line of site, and lesser distances when you have file cabinets or wall piping in between.
A Mac older than 4 years has issues with peripheral technologies as the PRAM battery/capacitor may need replacing. That can affect numerous peripheral technologies. It wouldn't be surprising if it affected the airport card.
A Mac that has had a logic board repaired/replaced, or was opened up for RAM replacement, could have its airport antenna accidentally disconnected, causing an issue with WiFi connectivity.
What other devices connect?
Have you look at:
Recommended settings for Wi-Fi routers and access points - Apple Support
What is the encryption method? WEP or WPA/WPA2
If it is WEP and all the other devices are non-Apple products, then this is a case of the standards body that created WEP did not specify how text passwords got encoded into hexadecimal keys.
This is a WILD GUESS, as WEP has been out-dated for many years and very few WiFi devices default to this encryption anymore. WEP is out-dated because it can be cracked in 60 seconds or less by any personal computer
WPA/WPA2 did specify the text to key encoding so a WPA/WPA2 text password works for all devices, and it is much more secure.
wifi will not connect to router
