Netgear D6300 dual band - fail to connect to iphone 4 (IOS 7.2.1)

[Difinity]

iphone 4 (IOS 7.2.1) failed to connect to D6300 router today for the first time.  Router now showing as 'netgearxxx-5g' rather than previously as 'netgearxxx'.  I have not updated anything though the router may have overnight.  No issues with other apple product (notebook, iphone 6).

iphone 4 can 'see' wifi network, but not able to connect - all router settings blank.  Performed Apple 'Reset Network Settings' without success.

any ideas?

[Difinity · Accepted solution]

Thanks. Problem solved for now. Was able to log in to the router and reset to 2.4g. Not sure how it got to 5g - (think that might have been Telstra though the tech at my local Telstra shop didn't seem to understand the bandwidth thing).
Saves us buying a new iPhone straight away.

Router supports both 2.4 & 5g, but doesn't switch between automatically.

This thread may now be closed. Thanks

[w3wilkes]

You should verify that your 2.4Ghz radio didn't get turned off somehow. If the device shows the 2.4Ghz radio active and other devices can see and connect to the 2.4Ghz radio you should try rebooting both the phone and router. If you still have the problem and no devices can connect to the 2.4Ghz band radio you may have a defective wifi router.

[Difinity · Accepted solution]

Thanks. Problem solved for now. Was able to log in to the router and reset to 2.4g. Not sure how it got to 5g - (think that might have been Telstra though the tech at my local Telstra shop didn't seem to understand the bandwidth thing).
Saves us buying a new iPhone straight away.

Router supports both 2.4 & 5g, but doesn't switch between automatically.

This thread may now be closed. Thanks