Most likely the power supply but first try hitting the CUDA reset button. It is located on the logic board between the front of the machine and the fan. Use a pencil eraser to do it.
Look in the upper left hand corner of the board. Go down to the second input socket , then just to the left of that. White button surrounded by silver square.
Most likely the power supply but first try hitting the CUDA reset button. It is located on the logic board between the front of the machine and the fan. Use a pencil eraser to do it.