vedecoid, I have considered that as one possibility but I just do not understand the mechanism at play that would lead to the failure. The connection failures have been noted on boards manufactured by Sparkfun which are certainly done by reflow. I can tell my connections are good and the repeatability of pushing the imp card into the socket or slightly tugging on it indicates something else is at play other than solder joint quality.
@mjkuwp94: I’ve noted (on the pin1 thread, I believe) that we’re tracking an assembly issue with some imps. If you have any examples of repeatable issues with pin connection, please contact us at email@example.com - we’d like to collect your imp (and sparkfun april, if applicable) for analysis. We’ll replace it with a new imp and electric imp-made april board.
Just a couple of quick follow-up questions as I may have now just experienced my first pin 1 intermittency. (Background: I don’t use Aprils, Sparkfun or otherwise … all my impees are home-built, using the Amphenol 101-00313-68-02 exclusively).
Has an actual socket problem been confirmed, or is the problem more likely Imp related (per @Hugo’s 5/16 comment)?
If Imp related, is there a visual inspection and/or measurement that can be used to identify potentially suspect devices? If socket related, do we know any more on this (perhaps based on the knowledge of what manufacturer’s parts are used on the various April boards available)?
At this point my problem doesn’t meet the threshold of a repeatable issue where I would send the Imp in for analysis. (I just reseat the card and it worked fine). A bit of time has gone by now since this issue has been discussed, so I’m primarily just trying to get an update on the status of the analysis.
It’s really not possible to determine whether an imp will have problems in the 4ucon or amphenol socket (I’m assuming the amphenol one has the same much higher spring force on contacts close to pin 1 just as 4UCON have confirmed theirs does). The differences really need specialized equipment to measure (deflection vs applied force on that area of the board).
If you are having issues then please contact info@ and we will get you a new card and you can return your one afterwards for analysis. We’ve improved the design in production so this shouldn’t happen again.
Thanks for confirming the problem is is more likely imp-side Hugo, and for the offer to exchange if necessary … swapping imps is certainly preferred over changing sockets. As mentioned, I’m not there yet, but now know better what to keep an eye out for … I’ve just recently had an elusive intermittent or two, nothing like the problems reported by others with Sparkfun Aprils. (Good to also know about the confirmed higher spring force of the 4UCON … just haven’t found a source for small qty’s of those … but Amphenol seems fine).
My initial question re: inspection or measurement was related just to the imp itself, not trying to measure any actual contact force. As you indicate an improved design was implemented at some point, I was just wondering if there might be a way to distinguish imps, either visually or by caliper measurement.
There’s no external physical difference with the improved design, so no way to tell, no. The test I was talking about (force/deflection) is on the imp card itself.