Multimeter Burden Voltage

KEITHLEY_196I just came across an interesting “real world” example of multimeter burden voltage. I have a nifty USB voltage/amperage tester that I was using to measure the voltage/current/power draw of my iPhone 5s connected to one of those rechargeable battery power packs, and I kept seeing the phone, after some time, would report “accessory not supported” and stop charging. For the life of me, I couldn’t figure out why1. The setup was running the battery pack into the USB tester, then to the phone. The USB Tester was plugged into my two Keithley 196′s, one measuring voltage, the other, current. Both were set to auto range2. When you first plugin the phone, it would draw about 3/4 of an amp. It would then slowly draw less and less as the charge got higher and higher on the phone. Then at some point, it would stop charging.

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  1. this is largely because I wasn’t paying attention to the meters all the time, so I didn’t notice the pattern right away []
  2. you might see where this is going now, if you’re paying attention []


FROG_black_bassinet-809If you’re used to my usual tech posts, you may want to skip this one, it’s a bit rant-y.

So, almost exactly a year ago, my son was born. And at that time, we were loaned a pretty wonderful stroller made by a company called Bugaboo. The stroller is a Bugaboo Frog, and it’s from 2004. It wasn’t cheap for the owners, costing nearly $1k. But, it worked through both their children, and there is no reason it couldn’t last through ours. One of the big selling points of these strollers is they’re extremely modular, and parts can be replaced relatively easily. We replaced a wheel a few months back that had it’s axle bent. Sure, it cost $50, but at least it’s better than replacing the stroller.

Queue the last few weeks. We had someone watching our son, and when they went for a walk, they didn’t know how to release the break, and as such broke the brake cable. Fine, I’m handy. I’ve worked on my fair share of bikes, it’s a brake cable. I found a video online for replacing it, and bought a brake cable, and some slip on ferrules, and tried replacing it. What do you know, the brake has a different insert for the cable. It looked like it just took a normal round brake end. Looking on the Bugaboo site, I found this video. That’s exactly my brake cable. So it should be available! I email them, and hear nothing back. I email again, and again, nothing. I try to use their chat on their site… it says it’s closed (even though it’s during their hours of operation). I try to use the contact form on their site, I get an Error 500 after submission. Fine, I post on Bugaboo’s Facebook page and finally hear back (from someone in the UK that is very helpful, but seems to only address Facebook questions once a day) that they did respond to my emails. Checking the logs on the server, I see the email was discarded as Spam. Awesome. They finally get me the content of the email over facebook, which is a bit odd, but whatever. Brake cable isn’t purchasable. I would have to ship the whole stroller (or at least the frame) to California (for the west coast), or New York (for the east coast) to have a place called Stroller Spa do the replacement. It’s a bloody brake cable, with simple ends. You have a video on your site how to do the replacement! Do they think I have another stroller to use while this one is being shipped off and repaired (which the total for something like that would probably cost well ever $100).

So, my question is, why are they making people send in their strollers to a service center for something like this? Why not have people do this for all repairs? I can order a whole new frame for the stroller… but I can’t order a brake cable.

So, I see a few problems that Bugaboo needs to address before I could even come close to recommending them (or right now, completely steering people away from them).

  • They need to fix their site. Their chat needs to work during the hours it should, and their contact form needs to work
  • They need to have the ability for people to replace their own brake cable if the stroller supports it. I could see not being able to replace a cable that required serious work to install. This one, they clearly have a video on their site showing how to do it.
  • They need to fix whatever is causing their email to be marked as spam. Unfortunately, I can’t tell them why it was flagged because it was snagged by our “black box” Proofpoint spam filter. But they need to contact Proofpoint to find out why (which I’ve relayed to them)

I’ll certainly update this if I hear any more from them, but at this point, I have an unsafe stroller. I don’t know what I’m going to do… carry a brick around to stick under the wheel when I need to stop? Only stop on flat car-free surfaces? I certainly know if I hear anyone that is looking to buy a Bugaboo stroller, that lives in the US, I’m going to steer them toward something else… a BOB or something, since at least REI sells those, and can work on them.

Update 1 (7/16/2014 12:41PM PST): Just tried emailing them a link to this article via their contact form. Error 500. Going on a week since I told them that their contact form was doing that. Tried their live chat, says they’re closed. It’s 12:41PM PST, and their chat says it’s open from “8am to 2pm pacific time”.

Update 2 (7/18/2014): Sadly, the Facebook exchange has resulted in the same contact information I already had, and no progress. I have emailed Bugaboo again asking for options (not just the OPTION of sending the stroller 700 miles to the Bay area to have the cable replaced). I see there are places to buy the cable online, but I would rather avoid that if possible, as I think Bugaboo needs to re-evaluate their policy with regards to these cables. I can, and am encouraged to, replace the buckles on my child’s car seat due to recall, buy I can’t replace a brake cable that would probably take less time? Anyway, more to come, I would assume.

Update 3 (7/22/2014): I have heard nothing back from Bugaboo, at all. I did email their official servicer, Stroller Spa, and got an email and call back from the owner within a few hours. While the owner was extremely understanding, and ironically said she had the same issue 8 years ago, there was really no way to get me a brake cable. Their contract prevented them from sending one, and said that the Frog was a bit of a Frankenstein in that things were kind of random, and cable length wasn’t set like it was in the later models. Basically, I’d have to send the entire chassis to have the cable replaced, and that would cost around $75 for shipping, and the work to be done. =/ So, while the owner was very kind, this still seems like a Bugaboo issue… and their argument this is a safety issue just seems ridiculous the more I think about it. So, I’m probably going to have to hack something so the stroller has brakes, which is, extremely sad for a nearly $1000 stroller.

Fender Mini Tonemaster® Amplifier Repair

Fender Mini Tonemaster®A coworker came in last week with a little mini amplifier (a Fender Mini Tonermaster®) that had stopped working. Being the curious sort, I opened it up, and looked at the main board. I immediately saw that D1 was physically blown (top half had blown off, and was rattling around inside the case). I figured this was probably the only issue, and brought it home to replace that diode (a simple 1N4003). After replacing it, however, the amp still didn’t work… which is why it’s nice I had it at home since I have the gear needed to diagnose the problem there. =)

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