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Macintosh OS/Macbook Pro w/ External Monitor


Hello, I have a 13 inch Macbook Pro a 2011 model with 8gb ram, 750 gb hd space, etc, and I am running OS X Yosemite. I am using a Dell monitor as an added external screen for my mac. When I try to move over screens that use internet such as safari or even the app store, the dell monitor screen starts to shake and goes black. It then shows a message saying its going into power save mode.  I then have to exit out of the window in the monitor screen by hitting command W or Q and wait for a while for it to display again. Can you please tell me what I can do to fix this issue? I was really hoping I could use this external monitor for a larger display, especially for things like surfing the web.

Yosemite causes many problems for users of older computers.
It was a major upgrade that currently has only one bug fix (10.10.1)
The number of problems is many and affect some and not others seemingly at random.
Another external display may solve the problem.
(the Dell monitor may be on it's last legs)
The resolution may not be set at the best resolution for the monitor.

Some diagnostic routines are:
1] Create a new user in System Preferences
  Login as the new user, test.
  If the problem still exists, it is probably a system problem, not a user problem.

2] Start up in Safe Mode and test. If the problem is gone, there maybe a plugin or application not made by Apple that is the problem. OR an application may not be the most Yosemite complient.

Post the problem at the Apple Discussions.
Search for "Yosemite Macbook Pro external monitor"
This restricts the search to this site.

Read the user reports on Macintouch on Yosemite

Revert back to a more reliable OS (Mavericks or Mountain Lion)

Should I Upgrade to Yosemite

Macintosh OS

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David Anders


Seattle - The Computer Guy - 15 yr veteran Mac/PC/network problem solving. Clients are design firms, artists, freelancers and photographers. PLEASE PLEASE provide EXACT info for Mac Model and OS Version. RAM installed - added cards - external devices - recent changes. Do you do MONTHLY MAINTENANCE? With what Utility? What you have tried and what result do you want.


First computer experience 1969. Worked in 3 computer stores. Setup First Mac and First IBM-PC.

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