I'm servicing my brother's DV6 6000 series laptop. I normally hate HP but I got this machine for pennies as it was in such poor condition. Its got a quad core sandy bridge i7, 8GB of memtest passed ram, HD7000 series GFX, a 256GB SSD, and a 1TB storage HDD. I've already tried reinstalling windows, and with no luck. It turns on, shows the windows logo, goes black for like a minute, then finally logs on. What on earth is wrong? I've also tried multiple SSDs, didn't help.