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Burnt Propeller Project Board USB - anyone? — Parallax Forums

Burnt Propeller Project Board USB - anyone?

ErlendErlend Posts: 612
in Propeller 1
I just - for the first time in five years - produced smoke. I know I will never get around to replacing the burnt chip, so I'll put it in an envelope and post it to anyone who wants it. As you can see from the picture it is populated with headers and a led-in-a-row IC.
PM me if you want it.

Erlendburnt.jpg
burnt.jpg
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Comments

  • SeairthSeairth Posts: 2,474
    Sending a PM.
  • ErlendErlend Posts: 612
    Ok. So, no more board - until next time...

    Erlend
  • MikeDYurMikeDYur Posts: 2,176
    Erlend wrote: »
    Ok. So, no more board - until next time...

    Erlend

    Think positive. ;)
  • ErlendErlend Posts: 612
    Good advice! - but I can live with the statistics of once every 5year too.

    Erlend
  • Heater.Heater. Posts: 21,230
    Don't worry. Us vultures are always ready to pick over the bones of whatever you kill next.
  • PublisonPublison Posts: 12,366
    I blew you of those regulators once. Some chipquik to remove and 10 minutes later I had a working board. Don't be afraid of SMD components. Be afraid of what made it go up in smoke! :) Shorted VSS VDD?
  • ErlendErlend Posts: 612
    Haste was what blew it up. Never a good way to work.

    Erlend
  • Heater.Heater. Posts: 21,230
    Yep. As the carpenters used to say "measure twice, cut once".
  • Peter JakackiPeter Jakacki Posts: 10,193
    Without wanting to deny the vultures a meal :) I would have thought this was an absolutely trivial thing to fix. You don't need anything fancy to desolder it either as blobbing solder onto the pins with a hot iron will make it float off easily. For larger packages it is just as easy to cut all the pins by pressing down on them with an exacto blade until the package comes loose and then a hot iron and a blob of solder picks up all the loose pins. So what you have there is like a loyal pup who was only scratched but now you've thrown him to the vultures!
  • DigitalBobDigitalBob Posts: 1,513
    That's a nice little board probaly would be worth fixing. Only what eight pins
  • ErlendErlend Posts: 612
    I am sure @Seirth will give it the love and care it deserves. I do not have that chip spare in my drawers, and I have too many projects going, that's why. I do not know last time, if ever, I was scared by electronics. Not even, aged 11, when I discovered the power of capacitors, as I dissected a TV and explored the 16kV citcuit.

    Erlend
  • Peter JakackiPeter Jakacki Posts: 10,193
    Erlend wrote: »
    I am sure @Seirth will give it the love and care it deserves. I do not have that chip spare in my drawers, and I have too many projects going, that's why. I do not know last time, if ever, I was scared by electronics. Not even, aged 11, when I discovered the power of capacitors, as I dissected a TV and explored the 16kV citcuit.

    Erlend

    Or venturing a bit too close to the anode of the CRT itself, the tube's internal capacitance packs a wallop!
  • Toby SeckshundToby Seckshund Posts: 2,027
    That's another thing that makes us sound old - Glass monitors, and having the tube out to play. You could either break the seal at the neck end, which made the tube sound like it was taking a sharp intake of breath, or chuck a brick at the skirt (and leg it) whilst taking a sharp intake of breath.

    Ahh, the bravery of youth, on old bomb sites ...
  • ErlendErlend Posts: 612
    -or place it face-up underneath a bridge and drop a sizeable rock on it - implosion!
  • MikeDYurMikeDYur Posts: 2,176
    Peter Jakacki wrote: »
    Or venturing a bit too close to the anode of the CRT itself, the tube's internal capacitance packs a wallop!

    Those were the days having to discharge them with a long screwdriver jumpered to chassis ground. You don't forget to do that more than once.

    Toby Seckshund wrote: »
    That's another thing that makes us sound old - Glass monitors, and having the tube out to play. You could either break the seal at the neck end, which made the tube sound like it was taking a sharp intake of breath, or chuck a brick at the skirt (and leg it) whilst taking a sharp intake of breath.

    Ahh, the bravery of youth, on old bomb sites ...


    I always heard that a break at the neck could cause the electron gun to shoot out of the screen. Never tried to prove that.
  • Cluso99Cluso99 Posts: 18,069
    You're even older if you can recall the old teletypewriter etc that the VDU's replaced ;)
  • ErNaErNa Posts: 1,752
    edited 2017-01-31 20:44
    Erlend wrote: »
    -or place it face-up underneath a bridge and drop a sizeable rock on it - implosion!
    I once tried to kill one, placed it in the garden and tried to hit it with a cobble stone. That was working very nicely, but I had to collect the thousands of splinters from the lawn over years. Happily they were not radio active!
  • Heater.Heater. Posts: 21,230
    MikeDYur,
    You don't forget to do that more than once.
    Assuming you survive. If you don't then you forget to do that exactly once. :)

    Having busted a few old TV tubes during my miss-spent youth I don't recall anything seriously bad or even exciting happening.
  • MikeDYurMikeDYur Posts: 2,176
    Heater. wrote: »
    Assuming you survive. If you don't then you forget to do that exactly once. :)




    I never got zapped personally, my boss said it happened to him.

    I was so careful, I used that same screwdriver to compress the anode clip to remove it. Worried about a residual charge. :o
  • ceptimusceptimus Posts: 135
    edited 2017-01-31 21:47
    A guy I used to work with was a roadie for a rock band - he used to set up all the amplifier gear. The valves (tubes) in the amplifiers used to work loose when the amps were transported so when he was setting them up he used to reach up inside them and push the valves back in to their bases. He said he got so used to getting a 'belt' from the discharging capacitance when he did this that on those occasions when he didn't receive a shock, he thought perhaps he'd not reseated the valves properly so he used to reach back inside for a second try!
  • Heater.Heater. Posts: 21,230
    Thinking about it now it's a bit odd.

    As a kid, 8 to 13 years old or so, everything was tubes. Radios, TV's, scopes, etc.

    As a kids of course we opened these things up and messed with them. And got zapped. It was annoying. Nobody ever told us it might be lethal!

    Somehow though I had the idea that the back end of a TV tube might be a different kettle of fish. Even if I had no clear idea of what volts and amps were at the time.



  • kwinnkwinn Posts: 8,697
    Cluso99 wrote: »
    You're even older if you can recall the old teletypewriter etc that the VDU's replaced ;)

    Oh boy....I do have a few memories of those mechanical monstrosities.....but not because I'm that old, just because some of the equipment I worked on was well past the age where it should have been replaced. I replaced a lot of them with Okidata 82 printers.
  • MikeDYurMikeDYur Posts: 2,176
    As a kid, If you ever touched the prongs on a power plug half inserted into an outlet (115-120VAC). It is a memory that is burned into your mind. Subsequent stupid moves like that seem to be intentionally forgotten.
    My grandfather told me he got across the house mains once(240VAC). He said he was lucky to be able to pull away. I always had great respect for doing work on both sides of mains. Take no shortcuts, Power OFF.
  • Peter JakackiPeter Jakacki Posts: 10,193
    MikeDYur wrote: »
    As a kid, If you ever touched the prongs on a power plug half inserted into an outlet (115-120VAC). It is a memory that is burned into your mind. Subsequent stupid moves like that seem to be intentionally forgotten.
    My grandfather told me he got across the house mains once(240VAC). He said he was lucky to be able to pull away. I always had great respect for doing work on both sides of mains. Take no shortcuts, Power OFF.

    Even though the project I'm working has its own safety cage area and a qualified person standing by with an LV rescue kit and warning strobes I find it all too easy to just forget all this and go to connect something inside the equipment even with its huge bus-bars snaking around the interior. That's because I've worked on it so many times unpowered except for the 24V supply to the circuit boards. I do avoid connecting serial USB directly from my laptop at these times though as I use serial Bluetooth instead.

    I keep meaning to hook-up a speaker directly to one of the phases with a suitable R+C just to remind me with a loud hum, otherwise the machine is "dead" quiet. There are no RCD safety breakers on this beast to save me!

    The fact that I'm still posting is a good indication I've been lucky so far....
  • MikeDYurMikeDYur Posts: 2,176
    Stay safe Peter, we need you here too.

    The grandfather I mentioned worked electrical maintenance at B. F. Goodrich in Akron, OH. The large mills and other machines required higher voltages than what a residential home would have. Probably what you are dealing with is the same. You would definitely have to know what your doing when the factory has it's own electric substation.
  • TorTor Posts: 2,010
    As for old TVs, tubes or not, the dangerous part was the live chassis. Getting zapped by the high tension voltage (color TVs were 25KV or thereabouts) was.. exiting.. but would normally just result in a smell of burned bacon. Not much current.
  • Heater.Heater. Posts: 21,230
    I always wondered about that. I was shocked (get it) to find that old tube radios in the US had no mains transformer and live chassis. As far as I recall all the tube radios I messed with in Blighty had a mains transformer. I have a couple of vintage AM sets here from Sweden and they have transformers. Not sure about the TV's though.
  • Cluso99Cluso99 Posts: 18,069
    kwinn wrote: »
    Cluso99 wrote: »
    You're even older if you can recall the old teletypewriter etc that the VDU's replaced ;)

    Oh boy....I do have a few memories of those mechanical monstrosities.....but not because I'm that old, just because some of the equipment I worked on was well past the age where it should have been replaced. I replaced a lot of them with Okidata 82 printers.

    The Flexiwriters of time were full of cams that constantly needed maintenance. Luckily I fixed computer boards, disc drives and videos, so my time was more valuable fixing them than Flexiwriters.

    The drum printers that were replaced by some of the Centronics Band printers around the same time as the solids ta 82 were enormous and heavy. They used to lift them with a crane through the big windows (after removing the windows of course).
    MikeDYur wrote: »
    As a kid, If you ever touched the prongs on a power plug half inserted into an outlet (115-120VAC). It is a memory that is burned into your mind. Subsequent stupid moves like that seem to be intentionally forgotten.
    My grandfather told me he got across the house mains once(240VAC). He said he was lucky to be able to pull away. I always had great respect for doing work on both sides of mains. Take no shortcuts, Power OFF.

    Got flung across the room twice when I tried to connect a neon light across bare leads plugged into the 240Vac. I was 9. Fortunately I never told my parents or I would most likely never have gone into electronics/computers!
  • MikeDYurMikeDYur Posts: 2,176
    Cluso99 wrote: »
    Got flung across the room twice when I tried to connect a neon light across bare leads plugged into the 240Vac. I was 9. Fortunately I never told my parents or I would most likely never have gone into electronics/computers!



    Oh yah nine years old, a very inquisitive time in life. Young enough to take daring chances, but not old enough to know better.

    The second time was because you were dazed and confused from the first time. We are all glad you didn't try for a third.
  • Heater.Heater. Posts: 21,230
    Luckily I got a belt from an electric cow fence on a neighboring farm as a young kid. My arm flew back and gave me a terrible punch. My immediate thought was that my young friend standing behind me had whacked me with a cricket bat. I wanted to do him some serious damage. Then I realized what had happened.

    With that experience I already had a healthy respect for that mysterious electricity thing when I started pulling apart, and building, tube gear a few years later.
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