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I have a strange error that often occurs during startup (about 50%) of the time, where my right monitor freezes, while the other works perfectly. I am using Snow Leopard on a Mac Mini. Any idea of what this could be or how to diagnose it?

My left monitor is using the default connector at the back of the Mac (I think its called HDMI). My other monitor is connected by VGA to a Lenovo Display Link Port Replicator (Model number K33415) and then via USB to the computer.

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Can you give more details about the hardware? Is this two monitors attached to a mac pro? or a single external monitor attached to a laptop? What sort of connectors? – Doug Harris Feb 9 '10 at 21:07
Updated the question for you – Casebash Feb 12 '10 at 0:24
up vote 2 down vote accepted

Well, the critical question is what is the USB to video device? What's the model number?

Is it?

I suspect that it needs an firmware upgrade, or driver software updates...

Does it officially support the macintosh?

From what I have found on the internet, that appears to a port replicator with video out... So the technical specifications only refer it to Thinkpad's for it's supported platforms... So don't expect IBM or Apple to support it's use...

That being said, I also found issues documented with Audio stuttering, and drop outs, when using it...

Please keep in mind, there are supported devices like the IOGear GUC2015V which have Macintosh drivers, and are quite affordable (for example, $50 at Amazon)... I don't see any reason that the Lenovo product wouldn't work, but have you seen any link between screen resolution & the lockups? My only reason for pointing out the IOGear is that your trying to use a device that has only been tested with Lenovo products, on another platform, where neither manufacturer will support it.

My first suggestion would be to test it with a 800x600 or 1024x768 resolution for a while, see if you can duplicate your issue then. USB has limited bandwidth, and it's conceivable that if there is a communications error (eg, too much data), that it could cause artifictating, or lockups...

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Okay, its a Lenovo Display Link Port Replicator (Model number K33415). I think that I should ask on their forums. – Casebash Feb 12 '10 at 2:16
Not officially supported for the Mac – Casebash Feb 15 '10 at 3:38

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