Help diagnosis power problem please

[JeffNYC]

I built my computer about six years ago--works for what I need in the near term even though it is dated. The other day the screen flickered and a second later I heard a small pop or spark from the computer case. Then dead. It won't turn on and the power fan and other fans don't work.

Think I'll be OK if I just reinstall a new power supply? Risk of damage to other components?

The power supply was Antec, I think 400W. Have these changed fundamentally in six years (connecting pins, etc.) that would make using a new one a problem?

Thanks for any guidance.