24" iMac won't turn on--screen blank

specs: 2007 24" iMac, core 2 duo.

history: had video artifacts, system would lock up at least every 3rd day (several apps open, like iPhoto, several web windows, movie trailers)

My wife was working on the computer yesterday (web/email), when the Mac just turned off. She tried the power button, it would not turn on. I tried the same, no boot up window, nor the little light was on. I could hear a very faint/slight fan noise if I put my ear right up to the computer.

I tried unplugging all USB (mouse/keyboard). I disconnected the power cord from back of computer, waited 10 sec, and plugged it back in while holding the power button'. I read that in the Mac support pages.

Same as before, nothing lights up, no screen image, I don't hear the HD booting, just a very faint fan noise.

Anything else I should try before making the Genius bar appointment?

Another note: If my guess is right, it'll be the MB that's fried...I think a $650-$850 repair? Can I save the data from my HD (ok, ok, I KNOW! should have had it backed up via time machine) All that said...should I wave good bye to the iMac and just get the iPad? Assume I can save the data mainly photos/videos)..how would I get that to the iPad?

It's hard to say what it could be although it does somewhat point to either the PS or logic board. It sounds like your iMac is not covered under Apple care which means that any repairs could be expensive. Take it on in to your local Apple store and let them give you an estimate of repair cost.

If the repairs are going to be too expensive, you can always remove the hard drive from the computer, put it in an external USB carrier and copy your data off it that way.

Regards.

So it turns out that its a bad power supply and logic board...at $772 repair. I decided NOT to repair it, so I pulled the HD out, bought an HD dock for it, and hooked it up to my PC running XP. downloaded MacDrive so I can transfer the photo files to the PC. But I can't locate the iPhoto photos on the HD...any ideas on where they might be? did the search using the XP search function, was able to pull the photo booth photos, but nothing else. Ideas?
And, anyone want to buy a 24" LCD screen for the iMac, along with the case/LB/etc minus the HD?

iPhoto images are within the iPhoto Library, and the last time i checked there was no way to open iPhoto Library in Windows (I just did a google search again, and came up with nothing, sorry)

I maybe wrong, there maybe a windows software or someway to open that iPhoto Library, but for sure, all your images are stored within that file thats called iPhoto Library in the Pictures Folder.

As mp04 has stated, your photos are contained within the iPhoto library which as far as I know, can only be opened by iPhoto.

What I suggest is to attach the hard drive you removed to another Mac (maybe a friend's machine) and use their copy of iPhoto to copy them to another folder which can be read by the PC.

Regards.