It has leaked out all its fluid, and has no gas. It has four flat tires and the body is all smashed up. The answer is never. It needs a mechanic, and His name is Jesus. Total Depravity does not mean that people are as bad as they can be, but that the total person, mind, emotions and spirit, have been completely affected by the Fall.
Man is corrupted completely and depraved totally.
All the faculties of man are evil, not just parts of him. So, there is no Gospel without bad news. We must get through the bad news before we get through to the good news about the Savior. The problem is that people want good news, then more good news, but no bad news. Jesus is the Physician for the sick, not the healthy.