i had compression, but no spark at all. No matter how much i'd push the starter, it would never fire up..
If you like pain
or are resistant to it , you can try to feel the sparks. i do it, if the spark gives a big jolt then it's good, if it's tingly or nothing =not good. But be sure to turn it more than 2 seconds, sparks are not meant to be conveyed through a human body so give it some time
Ah, maybe a safer way to check the box, smell it at the side of the connectors. If it smells chemical burnt, much much worse than the smell inside you Home Computer box, then it's toast too. Mine always started to smoke very strongly when i hooked it up to start the bike up with another battery, so it was 'obvious'
Post is a bit erratic, sorry about that. I hope this helps.
You know for 135USD a Box is quite safe, i assure you, they work as long as the code is exactly the same (10D00 [mine] for example) check it with your own box.