Wireless issues when plugging into Mac display

I have noticed that no matter where I am in the house, my Macbook Pro works with my Airport just fine. But when I plug the laptop into a 24" display, my wireless signal does one of two things: it drops a connection, going from full strength to nothing and back again, bouncing back and forth in a slow rhythm, or it will give me a huge drop in strength. Anybody have any idea why this is? Your help is greatly appreciated.

MacBook Pro 4,1, Mac OS X (10.5.6)

Posted on May 5, 2009 8:02 PM

30 replies

Nov 10, 2010 8:05 PM in response to poidogproductions

I have the same problem...

I have a 15" MacBook Pro which is connected to an Airport Express. If I connect to my 25" display, it disconnects my internet.

Any help how to solve this would be greatly appreciated, as I use two displays for FCP editing.

Thank you.

Kirk

Nov 26, 2010 9:50 AM in response to poidogproductions

My 15" MBP i7 is having the same issue. I'm connecting to an older 21" Princeton LCD display via DVI. Apple, what's going on here? The first post here is almost a year and a half old and still no resolution!

BG2000

Level 1

8 points

Dec 11, 2010 3:53 PM in response to poidogproductions

Whoa!

I had this problem, too. it was amazing. I have a new unibody that had major problems when plugged into a 24" cinema display circa 2005 (before the new glossy style) ... then when the computer was plugged into power the internet died completely.

I thought it was the new power supply style ... but no. Once the display was removed the internet blazed again off of my Airport Express.

ANYWAYS.

SOLUTION: Changed the channel on my Airport Express from Automatic (which was 11) to manual selection of 6 . . . and the internet is back once again!

Unbelievable! Thanks guys for figuring that out. That would've have been way down on my list for troubleshooting this issue.

URUTUM

Level 1

4 points

Dec 20, 2010 9:49 PM in response to poidogproductions

This is insane, seriously. I have been using my MBP and my LaCie monitor for ever without a single issue!! This just started and it doesn't make any sense on what could had cause this... a software update or something... but this needs to be addressed!!

Dec 31, 2010 6:53 PM in response to kaitob

I am having the same problem. I just got the minidsiplayport to DVI adapter and hooked the MBP (15" aluminum) to our 20" HP flatscreen. Painfully slow, and painfully obvious.

Y'all mention "changing the channel." Is this a switch on the router? I don't see it. I'm using a Netgear modem/router all-in-one installed by the folks at Time Warner (aka Road Runner?).

I'll try finding an ethernet cable and see how that goes...

love
nick

Dec 31, 2010 7:00 PM in response to TreeClimberNick

And just in case Apple doesn't believe us, I made a video documenting the prob...

http://www.youtube.com/watch?v=e5OuW96zFwQ

Dec 31, 2010 7:05 PM in response to TreeClimberNick

Just hooked directly to the router with the ethernet problem and the issue goes away. I have dual display AND internet connection....

however...the PROBLEM is still there. If I wanted to deal with this kind of crap and cables all over, I would've gotten the Macbook Amateur. But I didn't. I got the Macbook PRO. It should act PRO.

love
nick

mjlee

Level 1

40 points

Jan 1, 2011 6:51 PM in response to poidogproductions

Misery loves company. For xmas-2010, I have a new Macbook Pro and when I attach it to a new 27" LED Cinema Display, the wireless signal fluctuates and sometimes disappears. It corrupted my mail and interferes with my Time Machine Backup.

I read through all the responses in this thread. Sad to see so many users with the same complaint for 1.5 years and still no answer. I am trying to search Apple Support for "macbook wireless interference", but the knowledgebase hangs when I try to read past the 20th solution.

Jan 5, 2011 12:50 PM in response to poidogproductions

I ended up having to switch from channel 6 to channel 11 on my Netgear router. Unfortunately, since my router only operates at 108Mb on channel 6, I have to run it at 56Mb now.

Yeah, the problem is technically "resolved", so thanks (I guess). But still, something is up with the MBP that needs to be addressed by Apple. Keep the complaints coming and hopefully they'll listen to us!

Cheers!
Brian

Jan 12, 2011 4:33 AM in response to poidogproductions

Go here and complain..I did, Maybe if we get enough itll get through to them. I need this fixed soon 😟

http://www.apple.com/feedback

mucol

Level 1

0 points

Jan 30, 2011 2:15 PM in response to josephtlyons

I have two DVI connectors. Both looks same. I bought the 1st Connector at an 2008 Apple Store and the 2nd was purchased 2010 on Ebay (should be original,same price). The one from Apple Store works without any problem( Wireless and Display works).
If I use the second ConnectorCable than Display works but Wireless fails.
Perhaps it's helpful to know that this is not a Display Macproblem. Something to do with Connector.

mjlee

Level 1

40 points

Mar 14, 2011 6:36 PM in response to mjlee

I might have found a solution to the bandwidth drop that occurs when plugging in a new MacBook Pro to a new 27" LED cinema display. I was able to eliminate the problem by changing both the keyboard and the mouse that were plugged into the MBP.

The wifi in my house runs at 12Mbps via an Airport Time Capsule. But connected to the cinema display, the MBP was running at only 1 Mbps. I had an Apple USB keyboard plugged into the MBP. When I swapped out this keyboard for a new Apple A1313 wireless bluetooth keyboard, the bandwidth increased to 8 Mbps. Then, I swapped out the old Kensington USB corded trackball mouse for a new Logitech USB cordless mouse, and the bandwidth increased to 11 Mbps. When I plugged the old devices back in, the bandwidth dropped back to 1 MBps, whether they were plugged into the display or directly into the MBP.

Another curious aspect of this problem is that appears to also be related to signal strength. It first cropped up after we moved the MBP further away from the Time Capsule, from a distance of around 25 feet to a distance of 120 feet plus going through 2 walls.

Hope this helps.

Jun 2, 2011 4:43 PM in response to poidogproductions

I was having all the exact same problems of losing connectivity and or bandwidth when my external monitor was plugged into my 2010 MBP. I have confirmed that it is immediately fixed when changing the wireless channel on the router to something other than channel 11. I am using channel 9

edented

Level 1

11 points

Nov 30, 2011 8:02 PM in response to poidogproductions

This applies to a 2007 mac mini as well. I just plugged in a nice new monitor and lost wireless connectivity (despite claiming full bars). Strangely, the VGA cable with the dvi converter worked fine - full browsing capability - The screen just didn't look as crisp as it should be. Back to DVI cable.

My router is netgear n600 dual band. I switched over to the 2ghz broadcast (from 5), which helped significantly.

Switching the 2ghz broadcast to a different channel helped further. I recommend going through each channel and then running speedtest.net to see the results. I ended up best on channel 8.

Hope this helps someone out there...

Oct 22, 2012 5:24 AM in response to tomhedge

Switched the broadcast channel on Time Capsule from automatic to a static channel, and it appears to clear up the problem (instant increase in bandwidth of over 400%). Thanks for the tips, and good luck everyone.

MBP 15-Inch mid-2009; Mac OS X Lion 10.7.5; 23-inch Cindema Display 1920 x 1200l; NVIDIA GeForce 9600M GT 512MB

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Wireless issues when plugging into Mac display