My wifi drops when I plug in an external monitor through the thunderbolt port

Changing my routers channel fixed the problem for me. Not sure why.

joshemory what channel did you change from / to?

Edit: Sorry just saw in your previous post you went from channel 11 to 1.

Yeah, ended up going from 11 to 1 and it immediately fixed the issue. Again, I'm not really sure why that worked, but I was just happy to be able to use my monitor and wireless at the same time.

It is a Cinema display but, it is an older model the has an DVI connection. I am using the minidisplay port to DVI adaptor. I am using the rocketfish adaptor sold at Besy Buy. I tried one from Monoprice today and that seemed to make a small difference.

I am going to trade out the rocket fish for the apple adaptor tomorrow and see if that makes a difference. I'm also going to talk to the guys in the network operations center and see if they can make a channel change.

did you try changing resolution ? I just changed the resolution to anything but default and wifi started working again.

Yes and with no luck.

I might as well return the keyboard and track pad. If I can not use a external monitor, no need to have them.

Changed the wifi channel to 1, and no problem what so ever, no matter the resolution of the screen. Don't know if it works with the lid closed.

So changing channels is a solution, now if we could only figure out why the heck that was happening haha. Then we'd be doing Apples job.

I'm trying to use mine in a enterprise environment so changing the channel on the access point is not that easy. I just broke down and bought the USB to ethernet since I have drops at my desk. Obviously works like a champ now.

I changed my channel on my router this evening and will report back if I have any issues.

I am willing to try anything at this point.

So far so good!

Changed my router channel to 1 a few days ago and haven't had any issues since!

Not the best situation for people in enterprise environments but it seems to be a solution for me at this point.

Channel 1 is the answer to my problems it seems.

10 days in and I haven't had an issue since, lid open or closed.

Thanks everyone!

!

Same problem. My setup:

1. MacBook Pro Retina
2. Mountain Lion
3. External monitor attached via Apple Thunderbolt-to-DVI adapter
4. Network connectivity available via wi-fi only

Consistently, I could not connect to wi-fi with the Thunderbolt cable attached but could with it detached. I changed the wi-fi settings on my Linksys router to use channel 1 instead of channel 6 and the problem disappeared.

Thanks to all of you who posted before me and helped me solve the problem quickly!

Same here!

• Macbook Air late 2010
• new LG 27" HDMI Monitor
• third party hdmi adapter

Instant drop from 50Mbit to 2Mbit when connected, physical proximity is NOT important. Macbook can be right next to monitor (connected to Windows PC) and still achieve 50Mbit, only when it it CONNECTED the speed drop occurs.

Tried swichting channels, doesn't work for me (best I can do on other channcels is 5-8Mbit).

Solutions:

• Swiching to 5Ghz! Works like a charm. (but not good for me since my external WiFi USB Stick on my PC does not support 5Ghz)
• Connecting to Monitor (if possible) via VGA. Worse display quality but full 50Mbit.

This gets more and more confusing! -.-