Galaxy Note 4 sometimes turns off by itself


Jun 5, 2013
Okay, I own a Galaxy Note 4 N910U(Hong Kong version). I bought it from my friend 4 months ago who used it for 2 months. Now, the problem is ----

The phone suddenly/out of the blue turns off. For instance the first time it happened : I was watching a movie on it, left it on my bed, went to the loo, came back, pressed the power button, the capacitive touch keys lit up but the display didn't, it stayed pitch black(like turned off). I pressed the power button again, this time the touch buttons didn't light up, it stayed dead. So, I tried turning it on by holding down the power button, the blue LED lit up(like it does when turning on), I even heard the welcome sound but the display was just pitch black(nothing at all). Since the phone was making usual notification sounds while the display was black, I tried pulling out the battery & turn it on but the same thing happened, LED lights up, sounds are heard but the display is just pitch black.

So, I did some googling and found out that a common solution is to pull out the battery, hold down the power button for a minute, wait 10 mins then put in the battery. The first time it didn't work but the 2nd time it did. I was happy, but a few days later, the problem occurred again. This time the previous solution didn't work at all. After trying a few "hundreds" time, the phone suddenly turned on. But the problem persisted a few days later again. One of my cousins suggested that it might be a battery problem, so I changed the battery & the phone kept perfectly ok for a week or so then the problem came up again.

Any idea what might cause this really frustrating problem?
So from the math, the phone is 6 months old, contact where you got the phone from for warranty support or try Samsung. Could be a motherboard issue.