No crank signal, no volt reading on gauge

[Jnies]

hey all. 2004 trailblazer with a 4.2. I have a no start no crank. No crank signal at the relay. All fuses check out good. Battery is good. Replaced ignition switch. Headlights turn on along with interior lights. Radio does not work, key fob does not work. Any ideas on wear to start trouble shooting? Tried jumping starter relay and nothing happened

 

[Sparky]

When you turn the key to run (not try to start it) do you see the "service engine soon" light kick on and stay on, or not? It should be on, if it isn't the PCM isn't even responding.