Current Position:Home > IMac no longer detecting any networks...

IMac no longer detecting any networks...

Update:10-11Source: network consolidation
Hi again all...
My 24 inch white iMac recently went in for repair after having graphics issues (no other issue ever, everything perfect). It came back, switched it on, runs fast again and has no graphics issues.
However, Airport now does not seem to be detecting ANY network at all. Normally it would pick up my home network (router in the next room), as well as 1-2 other networks which are likely from other houses nearby. This has always been the same for the life of the computer. My MacBook has absolutely no issues detecting my home network as well as other networks, as per usual.
I have tried resetting the SMC, PRAM, removing and re-adding Airport, running Network Diagnostics, etc but it just cannot find anything at all. I even tried messing with my router a bit by changing the security a few times, the MacBook detected it fine again, but nothing on the iMac. Same thing after trying another router too. Also, the Airport card seems to be detected fine in System Profiler.
I cannot seem to figure out what's causing this and how to resolve it. Please can anyone advise me on what else I could try and what the problem could be?
Thanks, hope you guys can help!

The Best Answer

Try changing the Airport Channel.
Open AirPort Utility (Applications/Utilities)
Select the device you’re setting up on the left and then click Manual Setup. Enter the base station password if necessary.
Click AirPort in the toolbar, and then click Wireless.
Choose a new channel from the Channel pop-up menu.
If that doesn't help, go to /Library/Preferences. Move all the files in the System Configuration folder to the Trash, restart the iMac.
If nothing above has helped, try the Airport Troubleshooting Guide here.