Arduino Uno powers off when circuit plugged in to +5V and GND pins
and have the ... ISet(+resistor) and ground pins connected to the respective pins on the arduino.


What pin on the Arduino?

The ISet resistor should go to +5 V - don't connect it to an Arduino pin (unless you mean the +5 V Arduino pin). See diagram:



I had a 7-segment display working fine on an Arduino via the USB, see photo:



More details here: Interfacing LED displays with the MAX7219 driver