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Raspberry Pi Production Delayed By Factory's Assembly Flub 132

Posted by timothy
from the any-color-you-want-as-long-as-it's-magnet dept.
nk497 writes "The first shipment of Raspberry Pi devices has been delayed, after the factory manufacturing the cheap educational computer used non-magnetic jacks instead of ones with integrated magnetics. The problem is already nearly fixed, but new jacks need to be sourced for subsequent shipments, so those could be delayed slightly. 'It's inevitable, isn't it — you're freewheeling along perfectly happily and then you get a puncture,' said spokeswoman Liz Upton, apologizing for the delay."
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Raspberry Pi Production Delayed By Factory's Assembly Flub

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  • Why the magnetics? (Score:5, Interesting)

    by tecker (793737) on Thursday March 08, 2012 @09:31AM (#39287359) Homepage
    Can someone explain to me what advantage a magnetic 8P/8C connector has over a non magnetic one? I have no idea where this would be used. My cables have that little lock tab not a magnet. Does it not need the little tab anymore (that always breaks off)?
    • by prefect42 (141309) on Thursday March 08, 2012 @09:34AM (#39287399)

      I had the exact same thought and googled magnetic jacks:

      Molex Magnetic Modular Jacks incorporate wire-wound components (magnetics) in standard RJ45 jacks. These integrated magnetics, resistors and/or capacitors filter common-mode noise to provide signal integrity, protect PHY chips, provide DC isolation and offer low-mode conversion.

      I'm assuming that's the case here, and the magnets are providing filtering (given the cable's got a predominantly plastic and copper end it's not going to do much to hold it in place).

      • by Anonymous Coward on Thursday March 08, 2012 @09:36AM (#39287417)

        I'm assuming that's the case here, and the magnets are providing filtering (given the cable's got a predominantly plastic and copper end it's not going to do much to hold it in place).

        They're not magnets. They're tiny transformers and inductors that magnetically couple the signals while providing 1.5 kV DC isolation and some filtering against common-mode disturbances.

        • by prefect42 (141309)

          Ah yes, that makes much more sense. Magnetics isn't a term I knew.

          • isolation transfomers.

            had they said that, yeah, you want that in ethernet. products that omit that (popcorn hour, cough cough) have ruined NICs and bad performance for noise.

            in audio (spdif) you also want pulse transformers. same idea.

        • They're not magnets. They're tiny transformers and inductors that magnetically couple the signals while providing 1.5 kV DC isolation and some filtering against common-mode disturbances.

          Ahhh! ELECTRO-Magnetics. I wonder why that got left off.

        • by Iniamyen (2440798)
          Semantics
    • by MightyYar (622222)

      Conditions the signal, like the little donuts on monitor cables.

      • by ifrag (984323)
        For those cables, I think that would be a Ferrite Bead [wikipedia.org].
        • by MightyYar (622222)

          You are right - I probably chose a poor example since the donuts aren't magnets. Still, like the cable ferrites, the magnets in the connectors condition the signal off-board to free up space.

    • by Muad'Dave (255648) on Thursday March 08, 2012 @09:35AM (#39287407) Homepage

      As I stated in the other, non-annointed article and posted here [slashdot.org], the magnetics are actually tiny transformers used to convert from differential to single-ended signals and to isolate. Additionally center taps can be used for PoE.

      "The magnetics in question aren't to hold the connector in like those in a Mac power cord, but rather the tiny transformers that are required for Ethernet differential signal isolation/transformation."

      • by tecker (793737)
        AH! Had not considered the magnetics to be an isolation thing. Thanks Maud'Dave. Hopefully other will see this (or your other post). If I could post and mod I would rate this up.

        I feel a bit foolish now.
    • TFA claims without the magnetic connector the jack simply won't work. Perhaps the non-magnetic kind needs to be used differently in order to work.
      • Some controller IC's require magnetics on the PHY side in order to work at all. Others will work without magnetics, but only if short cables are used.

        If the Raspberry Pi circuit was designed such that the magnetics are responsible for 'pulling up' the output stages to the positive supply, then the Ethernet function simply would not have worked at all without magnetics in the connectors.

        BTW, 'magnetics' is a very common term in the field of electronics. It typically applies to inductors, transformers, and fe

    • All Ethernet interfaces must have magnetics. Having the magnetics in connector saves board space. Otherwise you would need a separate module between the Ethernet PHY chip and the connector.
    • by mcgrew (92797) *

      Does it not need the little tab anymore (that always breaks off)?

      That's someothing that's always bugged me. Of course you're going to need mini or submini jacks in a very small device like a transistor radio or an iPod, but I could never figure out why they didn't use RCA jacks in PCs. Not that RCA jacks don't sometimes fail. Heck, they could have used 1/4 inch jacks in PCs, I've yet to see one of those fail, even in a heavily used environment like a guitar amplifier.

      • The big problem with RCA jacks is that they are not keyed. You can insert any RCA jack into any RCA Jill. Sometimes that's not an issue, others, well, good designers know that it's best not to let end users think much.

    • I have only dabbled in electronics, but I don't care for the term "magnetics" (nor I have ever heard it before). I would think "inductor" would be a better term. Anyone who actually knows what they're talking about care to illuminate what the difference is between "magnetics" and inductors?

    • by gweihir (88907)

      Magnetics != Magnets. These are the Ethernet transformer coils that are missing.

  • Magnetics (Score:5, Informative)

    by Anonymous Coward on Thursday March 08, 2012 @09:33AM (#39287381)

    From the Raspi forums :

    "It doesn’t mean no network connection at all on all devices, but this board has been designed for a magnetic jack. The magnetic bits mean better signal integrity, better filtering and shorter transmission distances for data."

    "Magnetics refers to the presence of transformers and chokes which are used to isolate the Ethernet wires from the RaspPi’s power supply. and each other and probably to reduce high-frequency noise. Without them you would effectively tie the RX and TX signals together and probably turn the entire network into an aerial for Radio 2 reception."

    • "Without them you would effectively tie the RX and TX signals together and probably turn the entire network into an aerial for Radio 2 reception."

      I have no idea what this means. How is this possible?

      • Re: (Score:2, Troll)

        by Maddog Batty (112434)

        I have no idea what this means. How is this possible?

        I guess because you didn't study properly at school... ;-)

        "Without them you would effectively tie the RX and TX signals together and probably turn the entire network into an aerial for Radio 2 reception."

        I disagree with the first part of this. Ethernet works off differential signals and the transformer does a good job of removing the common mode signals (non differential) coming down the wire. Without the magnetics the common mode signals (such as DC, mains interference, Radio 2 transmissions) picked up by a potentially long ethernet lead will turn up at the input to the ethernet phy (receiver) chip. This may or may not be enough to stop it from work

      • by AlecC (512609)

        Its a joke. I think the fault makes the whole ethernet cable into, effectively, a dangling wire, and the only use of a dangling wire is as an aerial. Possibly connecting tx and rx makes it into a loop of sorts, and thus a loop antenna.

      • Re:Magnetics (Score:5, Informative)

        by Muad'Dave (255648) on Thursday March 08, 2012 @10:23AM (#39288113) Homepage

        Without the intervening transformer, the TX- and RX- lines would be tied together at ground on the device. In the diagram below, the differential RX+/- and TX+/- signals are turned into single-ended RX and TX by the transformers. Removing the transformers connects RX- and TX- to ground, which is a Bad Thing(tm).

        RX+_____3 E_______RX
                      3 E
                      3 E
        RX-_____3 E_____GND

        TX+_____3 E_______TX
                      3 E
                      3 E
        TX-_____3 E_____GND

      • Re: (Score:3, Informative)

        by Anonymous Coward

        Radio 2: UK radio station broadcasting crap music for housewives.

      • by mcgrew (92797) *

        RX is recieve, TX is transmit.

    • At least the forums are holding up now with new hardware ;-p

    • They also crucially provide center taps to provide a path for DC currents from the transmitter to ground and to give the receive signal the correct common mode level. Also because of the aforementioned center taps the pinouts of a jack with integrated magnetics will almost certainly differer from a plain jack.

      http://www.smsc.com/media/Downloads_Public/lan9000/9512_sch.pdf [smsc.com]

      (that is a reference design for the lan chip the Pi guys are using)

      So without the correct magnetics things are unlikely to work at all.

  • by Muad'Dave (255648) on Thursday March 08, 2012 @09:33AM (#39287383) Homepage

    The magnetics in question aren't to hold the connector in like those in a Mac power cord, but rather the tiny transformers [molex.com] that are required for Ethernet differential signal isolation/transformation.

    • by eclectro (227083)

      It would have been more informative to call the internal circuitry "filters" rather than "magnetics," which is conceptually more accurate.

      That said, this has to be great advertising for Molex.

      • by Muad'Dave (255648)

        They're not just filters, they're transformers that (as a result of their inductance and capacitance characteristics) also act as filters. I chose molex simply because they were first on the search and seemed informative.

        They've been called 'magnetics' in this context for quite a while - I guess it's a bit of an industry standard. They also have cute terms like PHY and MAC.

  • by Anonymous Coward

    I think many people, me included, have been expecting something like this to happen. As said in the article, this is a relatively minor bump in the road that was practically inevitable and they seem to be handling it as well as could be expected.

    I suspect they’ll get a bit of flack over the “4 day” thing... however they would have gotten a lot of flack if they came out with some information that turned out to be incorrect. I guess they could have come out saying “there is a minor pro

    • by ledow (319597) on Thursday March 08, 2012 @10:20AM (#39288073) Homepage

      Someone in China (the same guys that did the mistake in the first place, which most mentions have assumed to be a deliberate cost-saving measure rather than a true accident) has to receive those units back, hand-unsolder 10,000 connectors and hand-solder 10,000 correct connectors back into place before then packaging them up and sending them back to the UK.

      Where, still, as far as we know, there's been no tests of functionality other than networking (i.e. they haven't seen if similar issues affect the other ports like the display, etc.). And then someone has to test a good portion of them again before sending them onto the suppliers.

      Meanwhile, they have to source a supply of 100,000's of the proper connectors for future runs, which they are just starting now. And hope that the network WAS the only problem.

      In effect, they did no actual testing of the actual device functionality ("it'll all just work if the factory did their job") until the entire first batch was opened in the UK. The testing in the manufacturing facility was purely electronic and COMPLETELY missed this problem (surprise, surprise). And immediately upon opening them here, they spotted a problem, which took FOUR DAYS to isolate (and was isolated only because they were baffled and broke one of the connectors open and happened to spot the difference) and now it all has to be sent back for more work.

      That's a mite more than a "minor bump". Not irreconcilable, but certainly not a bump. More like a hard jolt with metal grinding. I sincerely hope it doesn't turn into another OP, but given that we've gone from "No preorders" to well, pre-orders, and a full launch to, well, we'll tell you when we have a working device in the same country as our distributors, the slippery slope has certainly started. Of course they can recover the situation. The question is, what other mistakes have they made in their supply chain of making 10,000 bare PCB's with components (something that happens thousand-fold times every day).

      • by Dave Whiteside (2055370) on Thursday March 08, 2012 @11:46AM (#39289425)

        Quotesdfrom the forum
        ''Jamesh is right – they sent us test units which *did* have the right part on before they moved to a larger batch. "

      • Re: (Score:2, Informative)

        by Anonymous Coward

        I hate to stereotype, but this is quite typical for China. You need to watch them closely or they will cut corners whenever possible.

      • by Viewsonic (584922)

        They probably wont be sending them back. They will probably be recycled.

      • by mydnite (531879)
        This kind of substitution happens all the time with manufacturing in countries outside of your own. Any one familiar with manufacturing in China, particular circuit boards, will know after the mistakes in the first run to always state in the manufacturing agreement "No Substitutions". Other wise you will get very subtle changes that while they look the same or perform the same are not what you spec'ed. The only other thing you can do is ask for the first 100 of the production run, not the engineering /
    • I'd have bet on supply problems.
      Always innovating, geekphone, and other manufacturers other than pandora had similar problems.

      A new company might overlook some details ending up in delays, the factories might be giving priority to big clients and go out of their way to not displease them, or maybe open hardware running open software is the #1 enemy for the modern models of marketing which rely on planned obsolescence.
      We ought to look whether startup hardware companies selling cheap closed stuff go on withou

  • by Chrutil (732561) on Thursday March 08, 2012 @10:17AM (#39288019)
    How do they work?
  • by Oswald McWeany (2428506) on Thursday March 08, 2012 @10:21AM (#39288085)

    Bye Bye, my Raspberry Pi,
    I thought that I might buy you,
    but the warehouse was dry,
    those good old boys say just wait one more month,
    but you keep running into delays,
    yeah, you keep running into delays.

    • At least I now have a reason as to why Farnell pushed my date back from April to mid May. All they did was inform me of the date and not provide a reason for the delay.
      • by Anonymous Coward

        Did you see the other recent post? There was a mistaken mass email by Farnell about pushing back orders.

    • by mcgrew (92797) *

      That was bad. Bad rhyming, bad meter. Try this one.

      Bye Bye, mister Raspberry Pi,
      Ain't as heavy as a Chevy
      but the warehouse was dry.
      those good old boys, they just want one more try,
      If I don't get one I think I will cry,
      If I don't get one I think I will cry.

  • Maybe they were using the wrong kind of tyres.
  • I was going to make a joke about suicide due to the shame of making this mistake, but then I remembered that this is a Chinese factory. DON'T KILL YOURSELF!
    • by Anrego (830717) *

      Shame.. or having to hand desolder/resolder 10,000 of these damn things.

      • by tftp (111690)

        or having to hand desolder/resolder 10,000 of these damn things.

        These connectors are nearly impossible to remove. Two large shield tabs + 8 (or more) through hole pins... It might be cheaper to scrap the batch.

        I'm amazed that this was allowed to happen. Mightily unprofessional. You never assemble a large production run of anything until the same people assemble a hundred boards from the same kit and then you personally test those 100 boards. Then they are returned as "approved" samples, and any deviati

  • by Anonymous Coward

    They advertise the hell out of their product, then they predictably can't deliver, then they silence any and all criticism on their forum (because not being all positive is "bad attitude", and they don't allow that), then another disaster strikes. I guess it's called karma.

    If you order now, you're going to get a delivery estimate about 3 months from now. Their mailing list had more than 100000 subscribers, and Liz Banhammer has the audacity to claim surprise when demand exceeds the initial 10000 batch.

  • Fucking magnets! How do they work?
  • by Rogerborg (306625) on Thursday March 08, 2012 @10:53AM (#39288591) Homepage

    Still good value?

    What about when the returns start flooding in because a 1 cent component failed when a 2 cent one might have soldiered on? Budgeted for handling that?

    I know these guys are amateurs, but do they really need to keep demonstrating it?

    • by petes_PoV (912422)

      Why do you assume that the same mistake - or one like it - would NOT have been made if the boards were assembled in the west? Since western wage rates are so much higher than chinese ones if this error had been made in a british or american plant it would probably be cheaper to simply crush the whole batch and start again,

      Then instead of a 1 month delay, you'd be waiting 6 months - or never, since the RPi foundation would have gone bust as it was banking on the sales of these units.

      • This sort of thing is precisely why the standard Slashdot rant of "all they did was put x, y and z together, this isn't innovating!" is so much silliness. It's not easy to mass produce things. It takes planning and more planning. It takes money and more money than you planned on because some small aspect of Murphy's law is going to pop up and rip your balls off.

        It's why the Motorola Xooms of the world come with stupid little missing bits and even why our fearless denizen of perfection, Apple, still screw

  • How many people are killing themselves trying to keep up production with the demand for Raspberry Pi.

  • From TFA:

    It's actually very hard to tell unless you look at the insides of the part,

    Ohmmeter?

    • by makomk (752139)

      Yep, that should do the job. Certainly a lot easier to get hold of than an X-Ray machine...

  • "Firstly, the schedule for manufacture for every UK business we approached was between 12 and 14 weeks (compared to a 3-4 week turnaround in the Far East)."
    http://www.raspberrypi.org/archives/509 [raspberrypi.org]
    [Posted on January 10th, 8.5 weeks ago - and manufacturing had already started at that point].

    I guess UK manufacturing wouldn't have been much slower, after all.

    RS

    • by asdf7890 (1518587)
      If they are referring to on-going manufacture as well as the first batch latency, then this bump is not that significant long term. If the order-to-deliver latency differs by 8-to-10 weeks generally then that can make a massive difference to stock control. If you might be waiting for longer to get new stock you would want to keep more in the warehouse in order to better deal with sudden bumps in demand.

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