AC adapter generates no LED light and no power.

I have an AC adapter from the first generation of Magsafe adapters. I plug it into a known working MacBook. There's no LED and the MacBook indicates it's running off the battery.

I jiggle the cord right in the "wrong" places - the area just outside the Magsafe head and the area just outside the transformer block. I can't get a reaction.

I was able to crack open that transformer block, but I can't see any electrical stress anywhere. I can't see any burning or scorching.

Is there a way I can test either end to see which one may have frayed interally?

I can probably perform repairs on the transformer side and the Magsafe side. I'm more experienced on the Magsafe side - I always strip off too much wire. I have yet to perform repairs on the transformer side. I'm wondering if there's any way to use the strain relief that sticks out of that transformer block.

Thanks for reading!