Fail Of The Week: Electrically Effective Emulators Exceed Enclosure, Enrage Engineer

After a few years of on and off development, [Steve] from Big Mess ‘o Wires completed work on a floppy disk drive emulator for older Macs such as the Plus. The emu plugs into the DB-19 port on the Mac and acts just like a 3.5″ floppy, using an SD card to store the images. He’s been selling the floppy emus for about the last year, and assembled the first several scores of them himself. At some point, he enlisted a board house to make them, and as of November 2014, he’s had enclosures available in both clear acrylic and brown hardboard.

[Steve] recently ran out of emu stock, so it was time to call up the board house and get some more assembled. After waiting six weeks, they finally showed up. But in spite of [Steve]’s clear and correct instructions, all 100 boards are messed up. One resistor is missing altogether, and they transposed a part between the extension cable adapter board, connecting it directly to the emu main board. But get this: the boards still work electrically. They don’t fit in the housings, however, and the extension cables are useless. After explaining the situation, the board house agreed to cook up a new batch of boards, which [Steve] is waiting patiently to receive.

2013-09-05-Hackaday-Fail-tips-tileFail of the Week is a Hackaday column which runs every Wednesday. Help keep the fun rolling by writing about your past failures and sending us a link to the story — or sending in links to fail write ups you find in your Internet travels.

20 thoughts on “Fail Of The Week: Electrically Effective Emulators Exceed Enclosure, Enrage Engineer

    1. EDN has a series of Fail articles. In one an LED would not function on a simple board. Engineer noted they were all installed backwards. Engineer fixed boards, asked mfr for better testing. Next boards, 50% fail, but mfr insisted all were tested and fine. Engineer noted fails were installed backwards. Engineer fixed failed boards – makes visit to see test setup. Show of hands – how many were expecting the AC power supply used to test the LEDs?

      1. *raises hand* I’ve had a similar issue with a supplier before. It was a control board that kept acting funny at random intervals. The clock signal was derived from the mains. The supplier tested it at 120v. The controller is rated 90-240VAC. It turned out the section that picks up the mains signal was only rated to 160VAC so they put in a voltage limiting network. It would work fine but when the temperature fluctuated, it would shut off, causing the clock signal to skip around.

  1. It really helps to send one populated set of boards/cables as an example when possible. It also makes it easier to argue about mistakes.

    Demanding the batch be free would be counterproductive. When you’re small, you pretty much have to ask nicely that they correct their mistakes. 100 units is not much at all… cause trouble (even if just demanding they fix crap that was their own fault) and the cost benefit quickly goes negative for them. The rework for this order has probably done that already.

    Also, it’s not at all clear how good the instructions were. Email bullet points (if used) are -really- bad ways to convey information to these people. They’re used to fabrication drawings, BOM files in CSV form listing all part numbers for each board, stuff/no stuff diagrams/pictures, etc.

    If the instructions were not in a normal format, then the fault is actually shared here. He might not have known, but then they usually don’t think it their job to train you how to produce the right documentation. The sales guy may think it’s -probably- good enough, but the floor is a different matter.

    Unfortunately, I had to learn through a long series of similar problems myself… always ASK THEM what they think went wrong, and if there was a better or more standard way for you to get the requirements across. Just saying “it was in the email!” is not the solution.

    1. Strange that they would have gotten it right the first time and then botched the second run though. I imagine it was sent over adequately and someone just made a mistake during fabrication without checking the order properly because they ‘remembered from last time’

      1. Happens all the time. Also send the sample. OR at least a high res and clear picture. Even then it can still happens about a year ago i got a few simple board assembled in china that the company had done before just fine. There was 5 boards on a pannel with 2 boards rotated 90deg.

        Unfortunately on 5 pannels the rotated the 32qfp micro 90deg on thous 2 boards that were facing a different direction. However it was partially my fault i shoudl have never had thous boards rotated to save a dime.

  2. I fail to see how this is a fail. Chinese board houses screw up all the time.

    I’d say that projects like the 3D printed surfboard are *far* more suitable for the fail category than this is.

  3. Previous FOTWs either had detailed writeups of how someone fixed the fail (or what they learned from it), or we were presented with an opportunity to help fix the fail. Which made them educational and engaging. Aforementioned altogether absent, alliteration an acceptable alternative? Absurd!

    1. I think I might be thankful that they didn’t “correct” the squirrelly USB connecter. First glance was that it was badly tacked on, but looking at the top silk screen shows it is supposed to be that way. I suppose there is a reason that it’s done that way; but without more explanation I am not going to say it was a “good” reason…

  4. I don’t think you can blame the design house for that, though – they seem to have designed a board with a MC34063 based switching regulator on it – and then whoever was assembling it decided to “enhance” it to provide (aproximately) 176% more voltage.

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