issue with minidisplay adapter and wifi

Have you checked with the manufacturer to see if the adapter is Mac compatible and whether or not they have a solution?

It sounds like there is an incompatibility and the adapter is causing issues.

Unless it is malfunctioning tis my line of thinking.

This thread caught my attention - because since switching last week from a late '06 Macbook to the Macbook Pro 13", my Wifi performance at home has gotten slow and unreliable.

I'm using the Apple MiniDP-DVI adapter, connected to a 24" Dell monitor, which has worked great for a few years on my white Macbook. My base station is a Linksys WRTSL54GS, located about 20 feet away from my desk.

So, I tried some speed tests with and without the DVI. Performance with the adapter connected is terrible, disconnected it's perfect. Further testing shows that positioning matters.

When the adapter is turned back 90 degrees, leading the monitor cable towards the back of my desk, Wifi performance is bad. When I turn the adapter so it sticks straight out the left side of the Macbook Pro, performance is normal.

This is a little weird, but an acceptable workaround for me.

Just the Macbook Pro 13" and Dell 2405 monitor - haven't noticed any other Wifi issues, but it's only been a week.

I've been fighting the same issues for the past month although I didn't link it to the DisplayPort adapter until a couple days ago. My network connection drops out and my Airport does not show up in the Airport Utility until I disconnect the adapter. The problem is intermittent for me which leads me to believe it is interference related as described above. If different orientations of the adapter lead to improved performance of wifi it sounds like RF interference. Also, I've tried both cheap MonoPrice adapters and an official Apple adapter with the same results. Also, I'm using a 20inch Dell display and an elevated laptop stand.

I had the same problems with a Monoprice Mini DisplayPort to HDMI adapter, and I was getting no internet wirelessly from the moment it was plugged in. As soon as I unplugged the adapter, I'd get internet again. I followed the advice of someone on another post on this forum (but I closed it so I can't find it again) and got it fixed.

They recommended changing the channel of the wireless signal on the router. After two or three tries I found one that worked (channel 1, lowest it would go) without a problem. Props to whoever had that suggestion, sorry I don't remember your name!

Hope this helps any of you guys with the same problem.

I'm experiencing the same problem with my 17" MacBook. The Mini DisplayPort is interfering with WiFi. Unfortunately I cant change my school's WiFi signal. It's weird that I can get more reliable connection by placing my hand over the left speaker.

Has anybody gotten this repaired successfully by the geniuses at Apple? I'm a little reluctant parting with it right now.

Thanks for the advice. I wanted to mention that this problem only appears to happen in the 2.4GHz range. Initially I thought my old Airport Express (2005) was the problem. I bought one of the new 802.11n compatible models and the problem went away. At the time I assumed that the old Airport was causing the grief.

A few weeks later I had to connect a device to my network that wasn't 802.11n compatible. I reconfigured the Airport to run at 2.4GHz instead of 5GHz. The problem returned instantly. After reading your post about dropping the channel to 1, this all makes sense now. The display port adapter must be emitting RF in the 2.4GHz range. Pretty lame. Anyone know where to find an FCC certified mini displayport to DVI adapter that does "not cause harmful interference"?

Dropping the channel to 1 fixed this issue for me!

I have this issue with 17" unibody.
A 3rd party displayport to dvi connector. Plug it in and the wifi starts losing packets and totally stalling.

Ha, score!
Worked for me too.

I posted this in another thread but found this one as well:

I am having the wireless problem as described when connecting to my external display via miniDisplayPort to DVI. Ive gone through 2 mDp-dvi cables (apple product and monoprice) with both having the same effect, as well as two dvi-d cables. I am hoping there is a fix for this as this problem just occurred within the last two weeks randomly.

So what does putting the router channel to 1 do for performance of the wireless? I will have to try that.

changing to channel 11 from 8 fixed my issue with the monoprice adapter.. off to the apple store to return their overpriced adapter. thanks guys!