Can't boot from any dvd or external hdd

Yesterday my dock dissapeared, and since I cannot drag and drop from one folder to another. Soon after many things began to go wrong on my Mac like major lags and everything. Disk Utility Verify Tool tells me I must repair so... i tried to repair from the installation disc.

This is what I get when I try to boot from the DVD (the image is in portrait while it should be in paysage...but you get the picture...sorry for the bad joke).



So I thought I'd try to restore from Disk Utility, by putting source files on an external hard drive I had lying around. Same result.

I then tried to boot from a bootable Drive Genius 3 DVD; the screen went black as if it would start but remained black.

Finally I tried to install OSX on my external hard drive thinking I could run the repair from there or run Drive Genius to repair it but after 45% the installation automatically restarts, or it's something else which went wrong because after the restart the installation does not continue. I have all .pkg's copied onto the external hdd but nothing else.

Does anybody here have an idea? I'm out of ressources... Thanks in advance

Details, details, details. None given. You didn't even tell us which Mac you have? Operating system version?

From your bare minimum description, it looks like your GPU may have failed.??

Sorry for that...Guess I was just thinking about what I just done.

iMac 27" ie5 3.06ghz core 2 duo september '09
4gb ram
1tb 7200rpm
Snow Leopard 10.6.4

GPU Failed? Do you know any way to fix that? Please let me know...thx for your time.

Rush it into your local dealer whilst still under warranty PRONTO!

Seriously? I'd really like to fix that myself if possible; the nearest Apple Store is an hour and a half drive from here...:S

Agreed with both the above. If the GPU has failed, there is no fixing it yourself. It's part replacement time. Need to call Apple or schedule an appointment at the Apple store and take it in.

Ok, thanks, but how can I make SURE it's the GPU who has failed? Can you give me some tests to do before I let go my baby for over a week at the store?

thanks.

anyone?

Uhm, look at the screen, but...

Intel-based Macs: Using Apple Hardware Test

However, if you can't see the screen, that's not going to help much either.