Why is the micro USB so fragile compared to mini USB cable ends?

Poutnik wrote, on Thu, 21 Aug 2014 07:18:51 +0200:

One thing I've just learned, from Jeff Liebermann, is to do the same!

Reply to
Avraham Bernholz
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cl wrote, on Thu, 21 Aug 2014 09:19:06 +0100:

I put a dab of the wife's pink nail polish on the USB top of the connectors, and, in the case of the less obvious device ports, on the device itself, where the pink dots are to be visually matched *before* one plugs in the connector.

So, at least in "my" situation, that's not why the USB nibs are failing. I think it's a bad batch of cables from Frys.

I found an unopened original cable still in its packaging from Frys (I had bought about a dozen cables at the same time):

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Those cables stink!

Roxgo,

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Manufactured and exported by Zendex, Inc, South El Monte, CA 91733, Made in China, UPC 851556004031

Reply to
Avraham Bernholz

I'd imagine that wherever you buy this kind of kit, and whoever is named as the "supplier", it's actually produced by some unknown factory (probably in China as things stand today, not that it makes any difference). And, more, that it won't always be the /same/ factory -- it'll be whichever offered to make the stuff cheapest.

So you really have no hope of identifying an /actual/ supplier, let alone of finding a good one.

But what you /can/ do is buy from a brand with a name that a reputation (good or bad) will stick to. Such brands have the incentive to monitor the quality of the stuff they are getting from the /real/ suppliers, and will switch suppliers if the quality drops.

Of course, even a brand might let a bad batch slip through: one with the wrong steel for the connector, or the crimping machine out of adjustment (so that it makes the crimps too sharp, and hence fragile). But that won't happen often /precisely because/ they are taking steps to avoid it.

Well, you answered that in your first post ;-) It turns out that micro-USB plugs have to be assembled to a certain standard or they stop working. (This is still on the assumption that something else isn't causing the breakage)

Can't make any recommendations. I generally buy cables in shops (not online), and avoid "cheap" shops at that, but I don't consciously buy by brand. As I say, I have had exactly zero problems with USB[*] so far (full, micro, or mini), but to what extent that's down to luck, differences in the way I use USB, buying higher quality cables, or whatever, I can't say.

-- chris

[*] Unlike bloody Ethernet connections...
Reply to
Chris Uppal

Chris Uppal wrote, on Thu, 21 Aug 2014 12:52:31 +0100:

I found an unopened package of the dozen or so cables I had bought from Frys.

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Roxgo,

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Manufactured and exported by Zendex, Inc, South El Monte, CA 91733, Made in China, UPC 851556004031

My recommendation? Don't buy those cables! :)

Reply to
Avraham Bernholz

Yup. European Commission to be exact.

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It's a not voluntary code though; it's an agreement between the manufacturers and the Commission. Probably because if there hadn't been an agreement, the Commission would have imposed a regulation.

Although true, I doubt any current smartphone is thick enough to accommodate a mini-usb socket.

Reply to
chris

That's probably un-necessary if you have a quality charger and properly designed cell phone. 0.1A inrush current is not going to do any damage to the gold plating. However, if you have a no-name charger, or worse are charging from a "stiff" 5v source, it's worth checking what the charger does. I have a USB extension cable where I cut the heavy 5V positive wire. I put various ammeters in series to measure current drain. Today, you can get such devices on eBay for very little: However, these will not show the required 0.1A inrush current limit or any current spike caused by an oversized capacitive load. For those, I insert a 0.1 ohm resistor (actually a length of nichrome wire). Using a dual trace oscilloscope, I put the Ch A probe on one side of the resistor, and the Ch B probe on the other, and the scope in differential (A-B) mode. That's necessary because grounding the +5V power line with the scope probe ground is not a good idea. I can post a photo of what it should look like if anyone needs a sanity check.

Note that USB 3.0 is different. Current is now up to 900 ma and overload protection is required:

Simulation of USB 2 inrush current:

The design of the micro-USB connector system intentionally moved all the failure prone parts to the plug. There's not much you can do to improve or protect the receptacle on the phone end, but plenty you can do on the cable and charger end.

There is an amazing amount of junk USB power supplies out there: The real Apple charger: and the not so real clone:

I bought a few cheap USB car chargers on eBay, and stupidly passed them out to friends as presents. After I looked inside, I had to run around and confiscate them before they blew up someones phone. Notice that there is a short across the data wires (used to fool the phone into believing that the maximum current available). The front has two USB jacks, labeled 2A and 0.5A. With the short, they're both identical. I tried to build an LTspice model of the device, but failed because couldn't identify the chip used.

I later bought some of these which are fairly cheap, and won't kill your phone:

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

Just try the foil wrapped box test and see for yourself. I think you'll be unpleasantly surprised. If you don't want to run the battery to total discharge, just run it for a few hours an look at the percent charge remaining on whatever battery monitor application you have available, and extrapolate the results.

Incidentally, don't try using an (unplugged) microwave oven for this test. They leak too much at cellular frequencies.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

Or, just buy a cable with a connector that fits both ways: Too bad it's only available for the large USB connector.

Or, just wait for the new Type C USB connector, which is reversible:

Find a microscope and look at the gold plating on the connector. If it's nice and shiny gold, you win. If it looks dark and dingy, like some of the base metal is showing through the plating, it's much too thinly plated.

Strictly speaking, the USB connector system is a bad joke. Ask any connector or switch manufacturer about switching DC with a gold plated connector and they'll cringe. Gold plating is suppose to be for "dry" loads (i.e. no DC). If one must run DC through a gold connector, the power is suppose to be disconnected and all caps are suppose to be discharged. For "live" loads, one is suppose to use silver. However, the USB connector has both a dry data load, and a live DC power load. Therefore, we see all the inrush current protection on the DC pins.

Before you declare your cables to be junk, you might want to run some bench tests with your five(?) assorted power supplies under various load conditions. Also check what they do for inrush current. My guess is that at least one of them will be problematic and possibly the culprit.

The thin USB cables may actually be an improvement. The higher resistance wire might reduce the inrush current a little. For short circuit protection, they'll probably make a tolerable fuse. I'm too lazy to do the calcs and measure the wire gauge.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

I bought a number of extension cables at the 99-Cents-Only Store a couple of years ago. Belkin, transparent plastic covering what looked like braided metal, lighted ends. Same package that I saw a few weeks later at Fry's for ~$14.00. I should have bought more of them, but the ones I buy from DealExtreme work just as well.

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Cheers, Bev 
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Reply to
The Real Bev

The 99-Cents-Only store had orange ones :-) They also had a variety of skins for one of the Apple or Samsung phones which ALMOST fit my BLU -- I gave the skin to my granddaughter, who has used it for months.

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Cheers, Bev 
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Reply to
The Real Bev

Where are you getting those from ?

Reply to
Rod Speed

Amazon and eBay. Available in white and Darth Vader black:

Grumble... I paid $15 and now the price is $10. Oh well.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

I'm getting bummed out on Duracell chargers and rechargeables. Several years ago (maybe 2008) I bought a set of the precharged Duracells -- supposed to maintain a charge while sitting on a shelf for nearly a year

-- and the spares (charged at the same time as the ones in my camera) are dead when the ones I've been using in my camera die. The Duracell charger (the BIG one!) stopped working within 2 years. I now carry more Kirkland AAs with me Just In Case.

Are the Eneloops any better?

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Cheers, Bev 
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Reply to
The Real Bev

Do you feed in the store as a destination? If not, how does it have any beter idea of traffic than you do by looking out the window? Or are you using one of the Sigalert/511 apps?

Theory has it that you maximize battery life by letting it run down to less than 30% and then giving it a full charge rather than keeping it topped up. What do you think?

--
Cheers, Bev 
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Reply to
The Real Bev

FWIW, I've never had any problems with cables -- or anything else -- from DealExtreme.

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There have been problems with some items right out of the box -- PS2 to USB keyboard connectors, and a never-could-have-worked mp3-player-to-cassettte adapter. I emailed them and sent photos of the items in question, and they credited me immediately.

The disadvantage, of course, is the 2-3 week shipping time. Big deal :-) They now sell some stuff out of their warehouse in California with much faster delivery, but if they're doing it legally they'll charge sales tax on that stuff, and I believe in avoiding sales tax whenever possible.

--
Cheers, Bev 
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Reply to
The Real Bev

Yes. I use them in my various cameras. Hardly any self-discharge after many months.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

So you got the cables from Fry's, who got them from Roxgo, who got them from Zendex, who may be the US marketing arm of a Chinese factory (or group), or may be another middleman sourcing cables (etc) from whichever Chinese factory is cheapest in any given week...

It seems that either you got rare a rouge batch, or that that entire supply chain doesn't include /anyone/ who cares as much about quality control as I'd prefer :(

-- chris

Reply to
Chris Uppal

I was hoping for bright red. :)

I had someone claim that the BNC cables I used on a job were his. I asked him where he bought the green RG/58. His jaw was just hanging open as I left with my tools and cables.

--
Anyone wanting to run for any political office in the US should have to 
have a DD214, and a honorable discharge.
Reply to
Michael A. Terrell

10/.99 = $.099 each, not $.05. Shipping was 79 cents, for a total of $1.78. The 10 I bought just arrived.

Solder, like Rod stated.

--
Anyone wanting to run for any political office in the US should have to 
have a DD214, and a honorable discharge.
Reply to
Michael A. Terrell

I thought someone wanted orange, not red ...

Reply to
Andy Burns

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