Machine specs: Mid-2011 MacBook Air with a 1.8 GHz Intel Core i7 processor, and 4 GB DDR ram, Intel HD Graphics 3000 384 MB, OS 10.9.2 (Mavericks).
Wifi connection is sluggish with multiple ISPs on various WPA/WPA2 networks (home, friend, family, etc.) but works fine on large public networks (e.g. Starbucks) as well as the university network where I am a student. My other apple devices (iPhone and iPad mini) work fine on the same WPA networks which are giving my 2011 MBA trouble.
After and in-depth search of this site and a few others, I’ve tried the following trouble-shooting steps to no avail:
- Hardware inspection of airport card by Apple technician revealed no damage
- Fresh “erase and install” of the OS 10.9.2 (did not use time machine backup out of fear of cloning the problem back onto my machine)
- verified and repaired permissions and disk from Disk Utility
- verified and repaired Keychain
- verified that the wifi was also sluggish in safe mode and restore mode
- hard reset of WIFI by erasing the appropriate system preferences plists
- created a “test” location in Apple network preferences; erased and created Wi-Fi in network preferences
- flashed the PRAM/ NVRAM
- changed DNS servers manually
- checked the activity monitor and ran Sophos Anti-Virus to check for malware, viruses, etc.
- turning off the bluetooth
- dragging the appropriate network to the top of the list
- renewed the DHCP lease from network preferences
- reset the MTU manually to 1453 (default is 1500)
- flushed the DNS cache in Terminal (dscacheutil -flushcache)
- turned the Apple security firewall on and off again
At this point I'm thinking it actually may be a hardware problem that was overlooked by the Applecare technician. Would it be worth buying a new airport card and installing it myself?
Thanks, all, for the help!