R
11

A simple trick for tracing intermittent faults I picked up at a hangar in Tampa

About three years ago, I was chasing a ghost in a G1000 system on a King Air. The PFD would flicker off for a split second, maybe once a week. I spent days on it, swapping LRUs, checking connectors, the whole deal. I was about to start pulling entire wire bundles when an old timer from another shop, watching me from across the hangar, just walked over and said, 'Kid, you're looking for a fire, but you need to feel for the smoke.' He handed me a can of freeze spray. I started hitting individual pins and small components on the avionics cooling fan controller, not the big stuff. When I sprayed one specific voltage regulator chip, the screen died for five full seconds. It was a bad solder joint that only failed when it got a little too cold from the AC duct right above it. I never would have found it without that methodical, localized temp shock. What's your go-to method for finding those random, heat-related faults?
2 comments

Log in to join the discussion

Log In
2 Comments
the_evan
the_evan17d ago
Ever try a heat gun on low to find a cold solder joint?
4
bethwhite
bethwhite16d agoMost Upvoted
Wouldn't that just melt all the good joints too?
3