MacBook Pro Stuck on Apple Logo

Hello,

I have a MacBook Pro A1286 on El Capitan.

For some reason it has started "boot looping" - IE it will get 3/4 of the way across the loading bar, then loop round and start again.

I don't appear to have a recovery partition of any description built into the hard drive.

I've done the PRAM and SMC reset to no avail.

I'm trying to boot from a Snow Lepoard disc that came with the Mac - I hold alt, and it detects the disc, so I select it.

From there, it simply gets stuck on the apple logo, and doesn't do anything.

Any advice?

Thanks in advance.