Mac Pro (trashcan) won't startup

My Mac Pro (trashcan) will not startup. I'm not getting sounds from the fan nor from the disc drive. The lights around the power button and ports are working but nothing else.

All the posts I've seen for Macs that won't start up discuss keyboard presses and monitor images. With my mac pro (trashcan) it doesn't come with a keyboard or monitor so I'm left with using HDMI to connect my TV and using a USB port to connect a keyboard and mouse.

In any case this means I'm using non Apple products for the monitor, keyboard and mouse. I think this is making the problem even more difficult to diagnose.

To summarize, my Mac Pro won't startup. And none of the help docs are helpful because they expect a keyboard, mouse and monitor which I have but do not seem to be helping.

Thanks for your help in advance.

Lou