New BBB crashes on boot + desktop

Hi all,
I recently acquired all the necessaries to use my BBB as a standalone machine (BBB A5C). To be more specific about my setup; I am using a 5v 1amp power-supply, and have a powered USB hub connected to the opposite end of the board (used for connecting keyboard/mouse). There is also a HDMI cable connecting the board to a screen.

Now I have a problem regarding board stability and booting. For example, sometimes when I push in the DC jack the single green light comes on, and then the other 4 leds flash about for about 10seconds and then suddenly the board goes dead. Pressing the “boot” button does nothing at this point.
Also; I once made it all the way to desktop then after a minute or 2 it turns off. This occurred after about 3-4 times of the above scenario had occurred.

I should also add, the flashing lights seem to stop at a particular sequence/pattern, but nothing on the screen says what’s wrong.

Please suggest to me what could be the cause, or what I should do. Thanks.