No Clock power and resetting is a definite sign of Main Fuse A 30amp power loss, located in the Starter Relay, it will also kill power to the Engine Stop Relay coil = Dead Engine, and power for the Starter Relay coil = No Starter Cranking.
Further info - Loss of Clock backup power and it resetting also confirms that the fault can't be an Ignition Switch problem, as backup power is Not switched through the Ignition Switch.
Check the Red plug at the Starter Relay. Check for any sign of heat stressed wires and burnt spade connections for the Red wire. Check the fuse and its legs for any signs of heat stress or poor/loose connections.
Even though you have replaced the battery it still could be an issue. What does the battery voltage drop to as you attempt to start the engine? Is your replacement battery a good quality item or Chinese cheapy? I've heard of a couple of new battery scenarios that were down on capacity straight out of the box, and not able to hold a charge, it may have been sitting on the store shelf for too long!
Let's know how you get on, good luck.