I purchased an imac g5 on ebay about 2 months ago. She said it's an older computer that is in good working condition except it may need restarted a few times every now and then. Everything worked fine for the first few weeks.. but now when I try to power it up it makes a loud crackling noise and freezes. After about 5 or 6 times of restarting it I can finally get it to start up correctly. But then my applications quit unexpectedly all the time.. especially safari.. and illustrator and indesign a lot too. I ran the extended hardware test and it fails on the memory.. any suggestions? Thanks!