Hi I got an early 2008 15 inch mbp (with removable battery). Some weeks ago I did a smart test for the HDD and it failed. Luckily I took backup of the data, because just recently the laptop when turned on gives a black screen and I can't do anything. I also have a failed battery, but I replaced that with an ebay battery I have been using up to the crash. I was playing diablo 3 on the mac and then some white lines showed up on the screen, and the laptop didn't react on any buttons I pressed so I shut it down manually. But when I turned it on again the laptop just showed a black screen. I have even tried to connect the laptop to an external monitor, but nothing happens. Question is, what causes the problem? The HDD? the battery? or has something happened with my graphic card?