Hi All Hoping someone with more knowledge then myself can help me work out what wrong with my 15" Macbook pro (model A1226, 2gb ram, 2.4 core 2 duo) running Lion. Since this morning I can't boot past the grey/blue screen with the apple logo and spinning wheel. Also weird vertical lines on the screen (see attached photo). It was fine last night when I put it to sleep but this morning when I opened the lid, the screen was black. I waited a few minutes but no change so did a hard reset by holding the power button for 5 seconds. Ever since then I've been unable to boot. Things I have tried include: Booting in safe mode (Holding shift) - Progress bar completes but then spinning wheel appears and eventually freezes Resetting NVRAM / PRAM (holding Cmd, opt, p, r) - Not helped I have tried booting from my setup disc which came with the MBP but its just being spat out, the disc is a bit scratched so thinking maybe it can't be read. I have run fsck by entering single user mode and typing /sbin/fsck -fy, but also no luck. I'm on lion and don't have an install CD, I tried booting from a snow leopard install USB but it comes up with kernel panic screen which asks me to force restart. I have only just recently had to replace the Nvidia chipset due to a black screen and no video output, wondering if this is connected somehow or if its something completely different? Any help would be greatly appreciated.