NEW09 imac External Monitor causes mouse to freeze every 4 sec for half sec

Okay, I found some more info about HDCP:

"When connecting 2 HD devices there is an exchange of keys and a specific encryption key is setup between the 2 devices before any HD content can be transferred. This is called handshaking. *The handshaking is repeated every few seconds*"

I think I'm on to something. I think I'm going to find a way to strip out the HDCP handshake and I'll report my results back.

Well, I think I have this licked... sorta...

I borrowed a 4yr old Dell 19" wide screen monitor and connected it via MiniDisplay port to DVI adapter to the 27" iMac and the herky jerky mouse issue is gone! I'm 99.999 percent sure the Dell does not support HDCP (0.001 percent unsure, since I can't find documentation to back that statement). In my mind it is not the iMac's video card or anything to do with installed software. I'm guessing that different manufacturers implement HDCP token handling differently and maybe the iMac has to generate a new token every 3-4 seconds, corresponding to the mouse and keyboard pauses.

I'm up to hearing any opinions anyone has. After all this I think 27" will suit me fine, even for FCP work, and I'll probably drop the second monitor all together. More than anything I'm hoping this exercise will help someone else.

I'm out.

Reading the last answer I bet we won't get any help from apple. They will tell us that it's not their problem...

I'm using a Fujitsu-Siemens 22 inches monitor and it's connected with the DisplayPort to DVI adapter and I can't get rid of that annoying mouse freezing... Here's my monitor turned off all day and waiting for a solution 🙂

Thanks for your work JerryMartin! I hope you can get to a solution and maybe get hired by Apple!

Hi, I'm not into hijacking post" but, the issue I had the Tech asked me to run the info program & email to him, this I did 4 times on different occasions:- end result "zilch"!! ended up taking the mac to the Genius Bar, Issue easily reproduced"" - they are still baffled after 6 weeks of tests & retests...I await another call from Apple...pretty soon I hope..prognosis -> I requested a New Machine, on the basis you cannot fix you must replace..L

I'm in the same boat with a Viewsonic 19" I'm trying to utilize. Hope we get a fix.

For those of us with LCD's that use a VGA cable instead of DVI or both VGA and DVI I just used a DVI to VGA cable instead and the mouse jerks have gone away. Obviously the problem is related to using a DVI cable/LCD.

At least for now the $29.00 VGA cable fix is working for me. For 20 years I have not been able to live without at least two or more screens. Ah!

I solved the issue pluging the monitor via VGA instead of DVI.... It's not a perfect solution but I can use my second monitor that way...

I have the same problem here.

iMac 27'' 2010
DVI adapter original Apple
Fujitsu Siemens L22W
latest updates
Problem appears "out of the box".

The problem doesn't appear in bootcamp windows 7


It should be very easy for Apple to reproduce it. A fix should also be a no-brainer.

Do they need more bad news about iMacs to get active?

I've been having the same issues here with my Dell 24" LCD, it has been working perfectly for a few months, but today it went back to its old habit of freezing every 3 or so seconds.

This is what I did to fix it. This has worked two times now, not sure if it will fix your problem or not, but here goes.

1. Have both the iMac and the external monitor on and plugged in - you should have the freezing issue.
2. Disconnect the DVI cable from the monitor
3. Disconnect the power cable from the monitor
4. Wait 30 seconds
5. Plug the power back in
6. Plug the DVI cable back in


This seems to work for me...

I read JerryMartin's posts about HDCP, and agree with what he is saying. Power cycling your monitor will reset the authentication cycle, and hopefully make everything work properly again.

Hope this might help someone. I know one of the last things I thought about was power cycling the actual lcd. I rebooted and unplugged the mac a million times, turned the power off on the front of the lcd, but never ripped the power cable out.

Cheers,
Matt

Anyone that is still not sure about this, JerryMartin's assumption is correct. It's being caused by HDCP not authenticating correctly (just as an aside - my Xbox 360 sometimes causes my TV to not boot for the same reason, so it's not just Apple at fault with this). Our 27" iMacs arrived in our workplace recently and we were getting the mouse stutter when using DVI on HP monitors, but not on any other brand we have around. So to use our 24" HPs with the new iMacs, we've had to drop them back to analogue.

This is really rather unacceptable for my mind, as it worked perfectly fine with our older machines. To fix the HDCP handshaking would merely be a firmware/software update for the MiniDisplay Port. So far Apple have not acknowledged this issue or even given indication that they are investigating it, so it would appear a trivial fix is still a long way off.

So for now, we're innocent victims of a faulty DRM system. Thanks for selling us out, Apple.

Despite the tone of my reply, I would be happy to assist in debugging this, but given that I'm not in the US or Canada, I am unable to lodge a support ticket via the phone and I can't find any way to lodge a ticket via email. I can provide straces / syslogs / whatever you require showing what is happening. Could the forum mods get a support tech to contact me via email so we can get this fixed for everyone?

pretenda wrote:
I've been having the same issues here with my Dell 24" LCD, it has been working perfectly for a few months, but today it went back to its old habit of freezing every 3 or so seconds.

This is what I did to fix it. This has worked two times now, not sure if it will fix your problem or not, but here goes.

1. Have both the iMac and the external monitor on and plugged in - you should have the freezing issue.
2. Disconnect the DVI cable from the monitor
3. Disconnect the power cable from the monitor
4. Wait 30 seconds
5. Plug the power back in
6. Plug the DVI cable back in


This seems to work for me...

Tried this. No go. Does the same thing. Guess its off to Best Buy to buy a VGA adapter. Hate to spend the money, but need the monitor and looks like Apple does not have a fix for this serious issue.

Picked up an Apple VGA-Mini adapter and the monitor now works, although I cannot get the correct resolutions to show up for the external monitor. Not sure why.

Really bad that I have to spend another $30 to get this to work.

Just got this from my Apple Tech who's been very helpful in trying to figure out information... I've done a lot of trouble-shooting with him, and he's been in touch with Engineering for the majority of the process.

This is the content of the email I just received:

"I just got a response from our engineers. They were waiting to give me a response because they were waiting for this to happen…

Update to 10.6.3 (just got released). See if this resolves your display issues."

Downloading now -- I'll report back...

Oh, and the update is about 750MB ...

YIPPIE!!!!!!!!!!!!!!

The upgrade WORKED for me!

Granted I have a special monitor (www.cinemaView.com) that has a mini-display chord specifically for the mac .. but I was having the same problems as described by others with standard DVI cables.

GOOD LUCK!!