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When I bootup my iMac I get a scrambled screen and after a few seconds the screen freezes. At first I thought this was a hardware issue but after reinstalling the OSX on a USB drive the OSX booted up normally. I cloned the defceted partition, reinstalled it and everything is working. The cloned one on the USB drive is still scrambled during boot. Although I have my data there are a few programs I cannot get back so I would like to get this issue resolved. Doies anyone have any advice?
This machine has daughter board video card that be changed. Here’s the part: iMac Intel 20" EMC 2210 & 2133 Graphics Card Here’s how to do it: iMac Intel 20" EMC 2133 and 2210 Video Card Replacement
Screen artifacts like what your second image shows is a sign the graphics VRAM is failing. Your system uses an integrated GPU chip on the logic board with its VRAM. Sadly you’ll need to replace the GPU board to fix this. Given the systems age and this is the last year for security support for El Capitan 10.11.x and Yosemite 10.10.x was last year. You should at least get to El Capitan. Or, think at looking for a newer system.
