Black screen for no reason

[Madison1221]

Sometimes when I’m on my laptop, the screen will keep going black and then will come back on. This has happened within the first week I’ve had this computer, (I’ve only had it for about 2 months), and now it keeps happening while I’m in class and it’s a major issue. I’ve noticed that I can adjust the brightness of the black screen while it’s black & you can tell it gets lighter and darker and I can still hear what’s going on on the screen, I just can’t see anything. I have done nothing to cause this, and I think I should be sent a replacement computer because of this issue. Please let me know what I should do.