For a system using a single GeForce GTX 660 (non-Ti) graphics card NVIDIA specifies a minimum of a 450 Watt or greater system power supply that has a maximum combined +12 Volt continuous current rating of 24 Amps or greater and that has at least one 6-pin PCI Express supplementary power connector.

Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! 

Overclocking of the CPU and/or GPU(s) may require an additional increase to the maximum combined +12 Volt continuous current ratings, recommended above, to meet the increase in power required for the overclock. The additional amount required will depend on the magnitude of the overclock being attempted.

The Antec EarthWatts EA-500D Green power supply unit, with its maximum combined +12 Volt continuous current rating of 37 Amps and with one 6-pin and one (6+2)-pin PCI Express supplementary power connectors, is more than sufficient to power your system configuration with a single GeForce GTX 660 (non-Ti) graphics card.

 

The GTX 660 on its own needs 140W from the 12V rail. For a complete system including that card I suggest at least a 400W or 33.3A on the 12V rail.

 

+3.3V@24A, +5V@24A, +12V@44A, -12V@0.5A, +5VSB@2.5A

 

In This example(picture) the power Supply is 600w but doesn’t have 38 a !

The graphic Card needs 38a

 

The Solution was , Change the Power Supply