Shorted 3-Wire Cable
ChrisL8
Posts: 129
This weekend while I was working on my Activity Board powered ArloBot I noticed that the Activity Board was off when it should have been on. I flipped the switch on the board itself on and off a few times, but the green lights did not come on.
I discovered the cause was this cable that was connected to one of the PING sensors was shorted between the red and black wires:
If you look closely you can see little wire strands sticking out through the black connector below the exposed metal parts. They are hard to see in the photo, but they show up as shiny lines.
These had touched and caused a short. When I pushed them apart the short was cleared, but of course I'm not going to use this cable anymore.
This was one of the cables that came with a PING sensor in one of the "Dual Ping/IR Acrylic Stand with Sensors" I used.
I checked both ends of all of the PING cables, and most of them had no wire strands sticking out, although a couple had some. None as long as the ones on this cable.
So if your Activity Board won't power on, check your 3-Wire cables!
I discovered the cause was this cable that was connected to one of the PING sensors was shorted between the red and black wires:
If you look closely you can see little wire strands sticking out through the black connector below the exposed metal parts. They are hard to see in the photo, but they show up as shiny lines.
These had touched and caused a short. When I pushed them apart the short was cleared, but of course I'm not going to use this cable anymore.
This was one of the cables that came with a PING sensor in one of the "Dual Ping/IR Acrylic Stand with Sensors" I used.
I checked both ends of all of the PING cables, and most of them had no wire strands sticking out, although a couple had some. None as long as the ones on this cable.
So if your Activity Board won't power on, check your 3-Wire cables!
696 x 623 - 237K
Comments
This is the first I've heard of this problem and I imagine debugging this problem could be quite complex for many of our customers because most people wouldn't suspect the cable being a problem. I'm also very sensitive to the quality of these cables because we use them to fly our ELEV-8 V2 quadcopters. I would hate to think that low quality causing a short or open could cause this problem and drop somebody's craft out of the sky.
We don't simply buy these on the open Chinese market. We know the supplier, very well. In fact, we can even send staff to their office if necessary. I've alerted Ari (who handles this for us) and he'll make the determination about what to do. I am certain that the quality feedback will make it to the company owner and to the staff who assemble the cables. Unfortunately (or fortunately, depending on how you look at it) getting these cables from the USA to you at a reasonable cost just isn't practical. However, I don't think the problem you encountered is a "Chinese problem" though many of us want somebody to blame. The same problem could happen in Rocklin if our staff assembled these cables. Truth is, most American staff won't assemble these cables day in, day out.
As for your cable problem which has been fixed, I know you don't need a replacement but feel free to ask us if you need one in the future. Always keep your expectations of our quality the highest you could expect and never let us off the hook for doing anything but the best products. There are too many companies that simply import and sell - we don't do that - we know the suppliers and carefully design these cables with them.
Ken Gracey
If you pull all the pins out be sure you put them back in the right order. Also notice there is a small arrow on the one side, this marks Pin #1.
I won't use it on anything that might fall out of the sky, but I'm sure it will be fine for my terrestrial robots.
I really just need to buy one of those multi-packs of servo extensions that Parallax sells, but I think I already spent this year's toy budget!
-Phil
Amen! Ebay is rife with just the cheap Chinese cables Ken is wise to avoid:
http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=servo+extension+cable&_sop=15
I have parts drawers full of various lengths. I haven't had any problems, but I wouldn't use them for mission critical apps either. They're cheap and plentiful enough to chop up and build into various projects.
ChrisL8, you're the first AFAIK to note this issue (and respectfully so, thank you very much), so don't think that one bad apple spoils the whole bunch.
NWCCTV, I would love to make my own cables but the crimping tool is rather pricey. Luckily that's a commonly used connector so I will eventually get a crimper.