iMac 21.5″ (mid 2010) Intel Core i3 4GB RAM with Radeon HD 4670 boots to white screen with vertical blue lines/bars:
Then it locks up after a few minutes, at which point the screen changes to white with these blue symbol things all over the screen:
If boot to Safe Mode, it still has the white screen with blue lines/bars, but eventually loads the login screen and I can successfully login and get to the desktop, but even that has the bars/lines.
Eventually, after enough restarts or hard shutdowns it will boot normally with no video/display issues. I’ve run disk checks, did the SMC and PRAM resets, checked logs (that I know of), and have even taken it completely apart, cleaned it out, reseated everything, put it all back together, but no change. I’ve read a few other posts about similar issues (but not quite the same video issue as this) where people had the logic boars replaced or reinstalled OSX, but that didn’t always fix it. Any ideas? Has anyone seen this issue before? Thank you.