ca16de ignition module

When I was attempting to revive the CA16DE in my 87 Pulsar, one of the things I replaced was the ignition module. Now that the engine is running properly, I was curious if the original module was indeed bad. So I took the new one out and replaced it with the old. The car ran fine for about a day, then stopped abruptly while idling in the Taco Bell drive thru (how embarrassing!) I pulled the car forward with the starter and after eating my tacos, reinstalled the new module. Fired right up and I drove it home. Does anyone know what exactly "goes bad" in the old module? Can I expect the new one to someday do this same thing? Should I keep a spare? I'm curious what all is hiding inside that expensive heat-sink-looking thing. If the malfunction is as simple as a bad solder joint, I'm gonna be pissed. Oh, well... at least I already had the new one to put in. It'd be wierd if i switch them again and the old one works for a while. Those intermittent failures can be a bitch to diagnose. Let me know what y'all think. If anyone cares to "drop some knowledge" on me, I'd appreciate it.

Michael

Your going to be pissed...
The most common ignition module fault is: dry solder joints. However, when the fail, they normally short out, frying the entire circuit and will either run on 1 less cylinder or just stop running full stop. With 10+ years of refinement in electronic technology, most new modules will probably outlast your motor ;)
PS: The solder join is so small that U could use a solder iron tip the size of a pin head and still bridge about 5 other joins!!

argg......i kinda figured.