Having problems with 21.5" i3 2010 distorted blank/rainbow pixel scre
Hi @mayer I am having a similar problem to what Sam reported. My iMac is an A1311 (EMC 2389) -- mid-2010 with 21.5" screen. Can you offer any tips on how to solve this issue? (Or whether it is solvable in the first place?)
Btw, I have posted a pic of my screen here: https://imgur.com/HokjRey
Mayer: raven, I have not seen that type of pattern before. Hook it up to an external monitor and let us know what you get.
Raven: Thanks [/User/13051/mayer|@mayer] I will give that a shot and report back.
Raven: Hi [/User/13051/mayer|@mayer], when I plug in an external monitor, the iMac still freezes before the login screen, but instead of a fuzzy screen with a rainbow of random color pixels, there is just a uniform blue screen (on both monitors). Any advice on what to do or suggestions on what the diagnosis could be? Thanks in advance
Mayer: Try booting in Safe Mode by holding down the Shift key on start up and see if there are ant changes. Next try holding down the option key and booting from the repair partition.
Raven: Hi [/User/13051/mayer|@mayer], I am able to boot into Safe Mode, the problem is that there is no graphics acceleration, so most applications are unusably slow. I can also boot into the repair partition, but I've already tried doing a clean reinstall of macOS (both the latest version of High Sierra, and the version that my iMac originally came with, Snow Leopard), but the problem remains. Ideas?
Mayer: raven, does your serial number match one of those in my original answer? How much RAM do you have? Have you ever changed the hard drive?
Raven: [/User/13051/mayer|@mayer] Nope, my serial # ends in 6DAS. 4GB of RAM. Yes, I recently replaced the factory 500GB HD with a 1TB non-SSD HD, using the iFixit guide and recommended tools. Everything else is factory original.
Here are the specs for my iMac: iMac "Core i3" 3.06 21.5-Inch (Mid-2010)