Murphy’s law of notebook connectors

Murphy’s law is an old time favorite of mine. Perhaps not always used as originally intended. In it’s most general form it says : “Whatever can go wrong will go wrong, and at the worst possible time, in the worst possible way”. According to Wikipedia the law was “invented” by an engineer who was testing crash test dummies and had to deal with devices which could be wired in several ways. Only one way was the right way, which led to Murphy complaining about his assistant “If that guy has any way of making a mistake, he will”.

Which sounds like a plea for plain unambiguous procedures, connectors and whatever. Have we learned ? A famous quote is “Murphy was an optimist”. Indeed he was. Take this.


These are the connectors of a brand new notebook and an USB mouse dongle which has to be inserted in one of them. The keyboard has nice backlighting but the symbols at the connectors are poorly visible and the slots look all very much alike.

Trial and error, from left to right

– The dongle almost fits. Perhaps I should push a little harder. Which will result in damaging my network connector.

– The dongle seems to fit, at least it does slide inside. I don’t know what pins I am touching and damaging while moving the thing around. My mouse doesn’t work as it is a displayport adapter.

– The dongle does not fit. This HDMI connector wouldn’t understand the pins anyway.

– The dongle does fit. Provided enough pressure is applied and I didn’t enter it upside down. My mouse even works, this is an USB adapter

– This connector does not only look like it’s neighbor, it is one of the same kind. Again, provided the right side was facing up, this will lead to success.

So 2 out of 5 might result in a working mouse and 2 out of 5 might result in hardware damage. What makes it even harder is that also the right way requires some force. That is a bad score, really bad. And things don’t stop here, my experiences in finding the right connector for an HDMI cable, working in the dim light next to the TV, are even worse.

All the form factors for these connectors were designed recently, long after the assumed common knowledge of Murphy’s law. Who was indeed an optimist.

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  • Adrian

    Why do mice still need cables, wireless keyboard and mouse adapters should be standard.

  • pvanooijen

    @James That’s just another example.. Complaining ? IMHO just noteworthy .. When will we ever learn ?

    @Steve .. Oh yes. The formfactor might be compatible but that’s not the end of it. “Unrecognized USB device”
    Or worse: The Motherboard connectors of USB and Firewire are form factor compatible. The pin assignments are not at all. Just try mixing that up. In case your’re lucky it will just ruin the motherboard, in case Murphy hits really hard you’ll smoke the USB circuitery of your $4000 digital camera.

  • Steve Py

    USB has always been annoying for getting it the right way around, more so when using vertical plugs on the backs of PCs. (on laptops just remember, symbol always up)

    My real beef is with memory cards and laptops attempts to support multiple card formats.

    My laptop has a single slot with: “SD*MS/Pro*MMC*XD” labelled above it. I’m like “WTF does that mean?” Then of course I have SD cards, and SD-HC cards which are not backwards compatible (oh Joy!) Does the laptop support, the HC? It’s an office-provided laptop, no manual, so try and find out. It does take a bit of force to get SD cards into the slot, a bit more than I find comfortable… Turns out it works. I have a multi-card reader at home attached to my PC because I have SD, SD-HC, and CF cards. The reader is arranged vertically and the only indication of which damn way the card should be inserted is to look down the slot and see which side the copper contacts are on. It’s as useless as EFTPOS/Interac/bank/credit card readers that can’t freaking standardize on whether the mag-swipe contact is on the inside or the outside.

  • James Curran

    What are you complaining about?

    You do remember that just a few years ago, the mouse & keyboard used IDENTICAL (but not interchangeable) plugs? (And it took a while before someone thought to make them different colors)

  • pvanooijen

    @Matt. It’s a Dell XPS with the lowest resolution available (720p) Very nice machine, o problems at all. To me full HD highquality notebook screens are no good. I cannot read the small fonts, I prefer a big screen for really watching something. This machine will drive any external monitor or TV.

    @Robert It would indeed be pointless for _you_ to post on this :)

  • Robert

    I also have that laptop, and curiously, have never made that mistake. Pointless post.

  • Matt

    I’ve just realised you have the same laptop as me. Do you have the RGBLED screen and if so, do you have any display issues, such as screen flicker?