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I have a rather strange problem. Occasionally when I boot, the GRUB screen has lots of black lines across it, and the screen is at a low resolution. If I let it boot through to Windows 7 or Ubunutu (12.10) there is no graphics card deteced. In all cases, rebooting works fine. In fact usually I just press the reset button at the GRUB screen and it always works.

It kind of seems like it should be a problem with the graphics card (GTX 460), except it always works after a reset. I guess then, something with the BIOS may be causing it? The motherboard is an Asrock Z68 - I'd have to double check for the exact model.

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Do you have any non-standard timing or voltage settings in the BIOS? – David Schwartz Feb 14 '13 at 6:18
Not that I'm aware of. Or, put another way, I never changed anything. – Juan S Feb 14 '13 at 6:43
Did it ever work right? – David Schwartz Feb 14 '13 at 6:46
Interesting question. It is intermittent, so I might go a couple of weeks without seeing it, but as far as I remember, it has been basically the whole time I've had the machine. (18 months) – Juan S Feb 14 '13 at 6:47
So it may be that the BIOS settings were never correct. You should literally check every single one of them. Who assembled the machine? (An amateur? The machine's manufacturer?) Were any hardware changes made after it was assembled (like adding RAM, for example or changing the graphics card)? Was a hardware diagnostic like memtest86+ ever run after the machine was delivered to its final location? – David Schwartz Feb 14 '13 at 6:48

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