Distorted lines freeze on boot

Question

I have an 2006 macpro, nvidia 8800gt, yesterday my mac froze during diagnostics by onyx, there were green and pink wavy lines on screen, i did a hard shut down then trying rebooting, but immediately i see green vertical distorted lines and the boot doesn't get past by the apple logo. it freezes and have to shut it down.
i've tried:
resetting pram, smc
removing half the ram and then the other half
installed a new hdd, didn't really matter the same
i even removed all hdd, the same
can't start from os x dvd drive, freezes,
the same for safe mode
it does enter verbose mode, still the same lines, but i can't read all the commands, it's like it's half towards the left and other half is at the far right, but only the first letter of the commands, it's like i have a second screen.
now 2 weeks ago, i had a similar problem but my mac didn't even boot.
i replaced my graphics card and it worked fine, but just for a week, then again the same wavy lines during mac os x environment
any ideas?
I'm desperate

Answer 1

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