2007-2008 IMAC I think will not boot past apple logo

When I start my IMAC it will load the bar but then show a folder with a question mark. Then if I try booting recovery by holding option it never loads. I have also tried internet recovery which I heard works but that does not work. It all started when the computer would randomly turn off. So I made an appointment with apple and they said it was the hard drive. Then they tested and it would not load and they then told me they could not help me because even the geniuses did not know how to fix the issue. They instead left me off worse than where I began. At least before they changed the hard drive I could actually boot up my computer now it wont go anywhere but stay on the same loading screen or the folder with a question mark. First picture shows me in the option part but the first one fails while the second recovery one never loads. The second image is it loading normally but leads to a folder with a question mark after a few minutes of waiting.