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Old 02-17-2004, 06:39 PM
TomJ TomJ is offline
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Join Date: Sep 2003
Location: Back in Colorado for now
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Re: Not enough solder is used and breaks after a few years due to vibration.

Quote:
Originally posted by dieseldiehard
The root of the problem with these climate control modules is due to the factory designing a mechanical joint that used solder to carry current as well. This is a NASA "no-no." To meet good manufacturing practices all electrical connection interfaces (ie. solder joints) are to be secured with wrapping a wire to a terminal or staking before soldering, that way the solder can't flex and crystallize (a well known phenomena.) Crystallized solder does not carry much (if any) electrical current.
This is not to be confused with a cold solder joint, it is a material fracture.
I have fixed several of these CC units, and the solution is always to resolder the butt-joints where the circuit boards on the sides meet the main board.
I believe flexing occurs when the buttons are pressed, the whole assy receives force that translates as stress on the joints and over time it fractures.
..................
Yep, that makes sense.
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