If anyone is having BIOS config issues like if you changed an option then saved and the laptop won't start, i'll give you some steps to follow to reset the BIOS on a Lenovo Y50-70.
***FYI: I haven't tried this on any other Lenovo laptop so feel free to try it.***
WARNING: *****For this steps i recommend a 2nd person to tell you when the laptop power cycles on and off for a few seconds on a couple of the steps below.*****
-Step 1: Open up the laptop and unplug the AC Charger, CMOS Battery, Laptop Battery and RAM Modules.
-Step 2: With everything UNPLUGGED, press and HOLD the Power button for 30 seconds.
-Step 3: Connect the AC Charger to the laptop and turn it on, at this point the laptop should turn on and turn off every 3~5 seconds, leave it like that so you can know the interval of time that you have.
-Step 4: While it's OFF, quickly connect the CMOS Battery, wait for it to turn on and off again.
-Step 5: While it's OFF again, quickly connect 1 RAM Module, wait for it to turn on and it should give you the "Lenovo" BIOS logo at this point. *You can wait until it reaches Windows to turn it off or just press the power button.
-Step 5: IF you're good, you can proceed to leave it OFF and connect the other RAM Module and the Laptop Battery.
-Step 6: Close your laptop undertray and power on and make sure to setup your BIOS once again because this will load bios defaults.
Credits: To a great dude in the Lenovo Forums on a post that was buried deep there and thanks god i found it, hehe. ☺