Hi I have a mid-2011 iMac which had been working perfectly until i moved home a few months ago. Yesterday I finally unpacked it from the box only to find out that it drops wifi functionality completely after 3 minutes, every time!
What's happening is that the iMac would have perfect wifi in the first 3 minutes after restart. Under the wifi list, it will show more than a dozen of networks found nearby, and automatically connect to my home network as normal. I can do whatever including hi-speed downloads at this time. However, after about 3 minutes, the wifi will stop all of sudden and the wifi icon will grey out. If I click this icon, it will show it's searching for networks, but none, nothing, not a single network name will show up anymore.
Turn wifi off and on again won't help. The wifi only comes back after restart, and then in 3 minutes it's dead again. Have tried deleting system configuration files, resetting SMC and PRMC to no avail. Have run Apple Hardware Test and the result is everything normal. Wifi Diagnostics won't tell me any problem either. All my iPhones/iPads connect to my home network without any problem. I don't think it is a Router issue because the iMac is able to see all networks in addition to my home network in the first 3 minutes, and then loses all including my home network - it's not like my home router rejects the iMac; it is the iMac suddenly becomes 'blind' to all available networks.
This is driving me crazy! What can be the problem here??? Thanks a million!
What's happening is that the iMac would have perfect wifi in the first 3 minutes after restart. Under the wifi list, it will show more than a dozen of networks found nearby, and automatically connect to my home network as normal. I can do whatever including hi-speed downloads at this time. However, after about 3 minutes, the wifi will stop all of sudden and the wifi icon will grey out. If I click this icon, it will show it's searching for networks, but none, nothing, not a single network name will show up anymore.
Turn wifi off and on again won't help. The wifi only comes back after restart, and then in 3 minutes it's dead again. Have tried deleting system configuration files, resetting SMC and PRMC to no avail. Have run Apple Hardware Test and the result is everything normal. Wifi Diagnostics won't tell me any problem either. All my iPhones/iPads connect to my home network without any problem. I don't think it is a Router issue because the iMac is able to see all networks in addition to my home network in the first 3 minutes, and then loses all including my home network - it's not like my home router rejects the iMac; it is the iMac suddenly becomes 'blind' to all available networks.
This is driving me crazy! What can be the problem here??? Thanks a million!
