Man this is timely. I was JUST dealing with this last week. Found a module that was giving me intermittent connection issues.

First thing I do after a big show is test every single module with a simple e-match to make sure they all fire. I label them with colored tape so I know which ones got heavy use and which ones were barely touched.

Biggest thing I found – check where your cables plug into the modules. The connectors get dirty and dusty, especially if you’re shooting in a field. I use contact cleaner on all of them before every show now.

Also +1 on the battery clips. Those spring clips lose tension over time. I replaced all mine with screw terminals this season and its been way more reliable.

Curious what module brand you’re running?