Why do I have no power to my motorcycle?

I have a 1980 Honda Cm400T it passed inspection a few weeks ago and I rode it two times after that. Then I parked it in my garage because it was getting colder outside, few more days later I tried starting it up again but once I turned the key in the ignition no power nothing at all, no lights, nothing. I renewed all the fuses, even charged the battery since it only had 12.03 volts. I don't know what else to check and why there's no power at all.

What Motorcycle exhaust is this?

Bike is a honda cbr 250

pictures:

What Motorcycle exhaust is this
What Motorcycle exhaust is this - 1
 - 2

anyone know what brand exhaust or any info on them?

Added (1). This is an aftermarket exhaust, was bought from 1st owner and 2nd owner doesn't know brand