1996 Toyota Corolla No Ignition

Hello,

My sons toyota died while driving, no dash lights when key was turned. Battery is good, I check ground connection of battery and positive cable. Door locks works only because it is hooked directly to battery through alarm's brain. We left the car and fiddle with it a few hous later and it started. Drive it 1/2 mile home. Now it is dead again and no dash lights or power to the ignition system. Could it be an issue with the ECU? I just need guidance as to where to check for issues since the battery is good. We had to replace the key ignition cylinder a few years ago becasue a key broke in the old one. However, the key turns fine but no power is getting to the ignition system.

Thanks