connections to android devices

[#1]

I have good broadband connection to Laptop but when trying to connect LG Magna android device it requests password  and after giving correct password the android device says it is invalid and will not connect. I had no problem with connections using this plusnet router to other android devices in the past and this LG magna smart phone has connected without any problems to other service providers WIFI routers. How can I fix this?

[#2]

when you type in the password are you waiting a few seconds before hitting the connect button ?
I ask because my kids had similar sounding issues and it was down to the entire password not being entered by the device and am wondering if your device is doing the same thing