Some new build gremlins are impossible to debug. There comes a time to throw it in the junk drawer. I've had a few of those and with new builds, if I flip a component into "never-never" land I've many times been able to desolder a replacement one from a project that never worked after building/attempted debugging. Sometimes best to move on. That's just the risk one takes when building electronic kits. Occasionally best to man up and start anew with a new kit. Oh, I've had a 100% success in 3 "salvage" cases doing this. It pays to get some modest SMT desoldering hardware and doing it by hand is possible if one is going to be building a lot of these kits. Cris knows his stuff and has been an excellent source for debugging his products.
Now if hardware dies in a lawn dart, best to toss into a junk box and start over. If a unit like a deployment altimeter seems to work after a lawn dart, put it in a "beater" rocket you don't mind losing for a flight test. If the "return to flight" launch is nominal then by all means use it. I had a fellow flier who ground tested a lawn darted deployment altimeter and it responded nominally. Put it in another rocket and had another lawn dart. He was experienced too and fastidious about deployment wiring. Fortunately used a "beater" for the test and that device too ended up in the junk box.
Don't do a return to flight with other associated devices like trackers as if it's off-nominal you may trash them too. Choose a beater rocket and motor for a "traditional", manual line-by-sight recovery.
The other option is fly a lawn darted deployment altimeter as a backup deployment device in a dual hardware flight. The backup lawn darted altimeter should fire the charges nominally on descent. In that case it's being tested under G forces and I'd feel more confident with that device. Use as the primary deployment device so your "good" backup is there to take over. Once recovered if all four charges fired, one is good to go. If only the "good" backup fired and saved the flight, the previously lawn-darted primary goes into the junk box.
Some folks don't have large enough projects to fly two altimeters so the best I can figure is up above for testing one.
Ground testing protocols in units that have them aren't 100% as outlined above. Sure, firing ematches on the ground ensures there is continuity of the ematch circuits but doesn't guarantee flight performance in a previously lawn darted deployment altimeter. Best to be cautious all-around. Kurt
