pic: Sidecar problem



Team 237 is on it’s 3rd sidecar. We found a problem was found with the digital side car capacitor (C6) wave-flow process. We found that C6, which appear to be a capacitor connected to the relay contacts of L1, was not properly soldered to the printed wiring board surface mount solder pads. This problem was noted on all three digital side cars that we examined.

Two cards that we examined found that C6 was loose and floating around on the card, causing a possible short circuit on one card.

Capacitor C6 was loose due to cold solder joints on one card and when touched broke free and detached from the solder pads. A closer examination showed that the C6 solder pads were shorted together with solder with capacitor C6 sitting on top of the short.

Technically that would be a solder reflow problem, not a wave-flow problem. :wink: Wave soldering is used to solder through-hole parts, whereas reflow soldering is used for surface-mount parts.

Looks like they may have a problem with their paste mask?

See http://forums.usfirst.org/showthread.php?t=10621

I don’t think that FIRST wants you to return your sidecars if that missing/loose capacitor is the only issue. The conformal coating on the board should keep any loose parts or metal filings (within reason) of causing any issues.

Did you have any other issues with the sidecar? Did it work fine otherwise?

Russ

It appears to be the only issue. Is C6 necessary and does removing it affect anything?

Kate from FIRST stated in the aforementioned Q&A link:

http://forums.usfirst.org/showpost.php?p=21004&postcount=8

Between two teams and ourselves we have 4 side cars that do not work. We were a beta test team and we are on our spare side car. We have made no wiring changes and the second car is working fine. The first side car worked fine for 4 weeks. We suspect a quality control or faulty design. We are going to buy two more because we are expecting them to go out. We are watching all the threads about this