My Samsung Galaxy J5 Phone is not turning on.

I have looked through many websites about how to fix these but the problem is non of them work. They all say things such as hold down - Power Button + Home Button + Volume Down Button - but none of these work. I have tried many things and this has happened before but I cannot remember how to fix it. I need to fix my phone because I would not have enough money to buy a new phone. Oh, and i tried pushing down the Power Button + Home Button + Volume Down Button for the first time and it just flashed a light blue screen for around half a second, after that it hasn’t done it since.