15
Found a weird trick for a stubborn LRU fault on a Garmin G1000
Had a Citation in Wichita with a PFD that kept dropping out, but only above 15,000 feet. The book said to replace the whole display unit, but I remembered an old timer telling me to check the backshell pins for cold solder joints. Took the connector apart and found pin 22 had a tiny crack you could only see with a 10x loupe. Reflowed it with my Weller station and the fault cleared. Anyone else fixed a high-altitude fault without swapping the box?
3 comments
Log in to join the discussion
Log In3 Comments
riverperry7d ago
That's a good find, but swapping the box is still the right call most of the time... a reflow is just a band-aid if other joints are ready to go. The approved fix exists for a reason, to prevent the same fault from popping up somewhere else later.
8
maxmurphy7d ago
Saw a tech breakdown last week that basically said the same thing. They pulled apart a bunch of units with the same known fault and found weak joints all over the board, not just the one that failed. Fixing the single point just moves the problem. Makes you wonder how many "fixed" boards are still out there on borrowed time.
8
gavinm899h ago
Been there. Had a whole batch of those boards come back after the "fix". You reflow the main chip, it works for a month, then a memory joint goes. The real move is to check the whole board under a scope for other dull or cracked solder. If you see more than one iffy spot, just replace the whole thing. Saves the customer a second headache.
6