Is there ANYTHING that can cause loss of compression in one rotor OTHER than a blown seal?

My stock 88 SE N/A started running rough and would not idle unless you kept you foot on the gas. When I forst looked at it, it appeared that no spark was getting to the trailing ignitors and I got no tachometer signal.
I had no choice but to drive it home this way.

Later, all igniters were getting juice, and I had tachometer. But a mazda mechanic says there is no compression in #2 rotor.

I saw a thread that mentioned carbon lock. What's that about and could it have resulted from the ignitor problem causing loss of compression?

The car starts right up, and runs rough. but there is no smoke or leaks.

Please HELP ME. Is there any way to save this engine?

It is stock with only 123K on it.