MacBook Cannot Boot Up - Grey Screen My MacBook won't boot past the grey screen (white unibody MacBook 15", Intel-based, dual core).

I installed an illegal copy of Snow Leopard onto my Mac (as legal copies were not available in my country at the time).

It doesn't boot up anymore, but sometimes when I hold down the option key it boots.

I've installed linux mint onto it, and it works – or rather it worked fine.  More often than not it doesn't even boot into target disk mode (no hard drives appear nor the Mac installation disk).

More often than not it doesn't boot the os installed or reads the installation disks. Its just a blank grey screen. No icon or anything.

However on the rare occasion that it does boot as it should in target disk mode, hard disk appears and if an installation disk is inserted, it is read perfectly and after selecting one of the targets, it boots fine. Problem is, this normal boot only occurs like 1 out of 30 attempts.

I have tried:


Resetting the SMC - can perform
Resetting the NVRAM and PRAM - can perform
Boot into safe mode - cannot perform
Boot into verbose mode - cannot perform
Removing the battery and holding the power down for a minute
The simple answer is it sounds like your operating system is totally fried. You will need to do a full erase (zero out all data and not the quick erase drive option) of your hard drive. Reinstall a legal copy of Mac OS X. This is absolutely key. It's just plain out not smart to install anything illegal. It is so easy to add key logging or any other type of malicious software into illegal copies of operating systems. Furthermore, they could easily install stuff that could grab personal data such as passwords, bank account information, or use your computer as a zombie to hide illegal activity. You could get easily screwed. Do you want that? I don't think so. Who would? Just buck up the cost and get a legal copy of OS X. It's worth every dollar and the peace of mind. 

If you can't afford Mac OS X install a stable build of Linux, but I scratch my head as to why would someone have a Mac but not run Mac OS X as their primary OS. Doesn't make sense. You might as well have a PC.