GT125R 2007 "rear coli, no spark"

My brother have bought a GT125R 2007 rep object very cheep.

Because the previous owner couldn’t get it to start..

I found that the rear coil wasn’t giving spark, so I changed both coils for the upgraded coils.

But I now think it’s the cdi..

do enyone know how to test the cdi?

attaching some photos.