ahh y400..same here brotha..

me and my 2 housemates, all use Lenovo Y400..one bought new set, while me and the other one bought secondhand units (around 1 1/2 year old)..

all have problems within 1 year, even the new set

all have cracked assembly case near left hinge (punk-ass lenovo doesn't want to cover warranty for this even though almost all laptops of this model have the same problem)

some keyboard button's not responsive

then one by one, our laptops start to suffer abrupt shut down (no BSOD, just shut down) after several minutes of gaming or medium-high graphic related work

sent to Lenovo service centre, laptop's only able to hold on for just two weeks after acquired it back from service centre before suffer the same problem again..

can't claim warranty anymore afterwards coz expired

sent the laptop to a friend to clean the dusts inside and reapply quality thermal paste..still doesn't solve the problem..

weird thing was, after around 2-3 months, this 'abrupt shutdown' problem fixed itself. I don't know how but till this day, even when i play games like Battlefield 4 that eat up graphic resource and totally heat the laptop up, it works fine..

I've also replaced the cracked assembly case, ordered the spare parts from China..

still, never gonna buy Lenovo products again after this