ios 9.2 wifi connection problem

[DonkeyChainsaw]

Hi everyone,

A few days ago we switched from internet provider (from ADSL to Cable), But since we have switched all apple devices in my home can't connect to the wifi. It includes an ipad 2, ipad 3 and a ipad air 2. Every time i insert the password it says the password is incorrect, but i know i inserted the right one. And the other weird thing is that after a few tries i did get in but it disconnects the whole time. The wifi logo appears for a few seconds but then dissapears again. What can i do to solve this? I have tried: resetting the modem and the network settings on the ipads. I also put the wifi security settings off (so no password was needed) this worked to connect but i still couldn't load a web page. What else can i try? I have no problems connecting android or windows devices.