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Welcome!What Hardware version is your router? Look at sticker under router.
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Firmware version is currently loaded? Found on routers web page under status.
What region are you located?
Channel Width set for Auto 20/40Mhz or try 20Mhz only.
Try setting a manual channel to a open or unused channel. 1, 6 or 11. 11 for single mode N if the channel is clear.
What security mode are you using? Preferred security is WPA-Personal. WPA2/AES Only. Some WiFi adapters don't support AES, so you might want to try TPIK only or Auto.
Try disabling ALL Wifi security on the 835 and test to see if the device will connect then.