No power shown at all in my optiplex

I recently installed a new power supply in my dell optiplex (my new computer) and there is no motherboard lights on, no fans start when I press the power button and I have ruled out that is a power by completely unplugging many things and still having the same problem. All I have seen is the amber light with different patterns of lighting up and have done many different solutions to the amber light and still no effect. Is this a fried motherboard or something else?