I learned to be extra careful with IC chips pins

Discussion in 'Homework Help' started by pfelectronicstech, Oct 10, 2012.

  1. pfelectronicstech

    Thread Starter Member

    Jan 18, 2012
    178
    4
    One thing I learned so far in the hands-on part of the program is be extra careful with IC chips. I put the IC 7473 in and wired it up the way the book described. I was 100% sure it was wired right, but only 2 of the 3 LED's would light. I checked, and checked, and rechecked the wiring, and could not find an issue. I then took out the IC 7473 and 2 pins were bent, and not in contact with the breadboard. I thought I was screwed, but I got out some needle nose pliers and fixed the pins, re installed and all is good, everything worked. So I learned two things, be extra careful with the pins, which was mentioned in my text books, and I learned how to and that I can fix the pins. I was quite proud of myself. I know not much to you veteran Techs, but it was cool to me. I learned to troubleshoot, be careful with pins, and I can fix the pins. Just wanted to relay that.
     
  2. nsaspook

    AAC Fanatic!

    Aug 27, 2009
    2,907
    2,165
  3. MrChips

    Moderator

    Oct 2, 2009
    12,429
    3,360
    I get to see this many times from students - one of the trickiest problems to solve.
    I have seen this enough now that when I probe with a scope I don't probe the holes on the breadboard but go for the IC pins themselves.
     
    pfelectronicstech likes this.
  4. DerStrom8

    Well-Known Member

    Feb 20, 2011
    2,428
    1,328
    Just be careful now. One the pins have been bent and moved back, they are bound to break easily. I've had many of my chips lose their pins entirely. Be very careful when placing the chip on, and removing the chip from, the breadboard in the future.
     
    pfelectronicstech likes this.
  5. pfelectronicstech

    Thread Starter Member

    Jan 18, 2012
    178
    4
    Thanks, I was very worried about the pins breaking off. To be honest I thought when I went to bend them back in place they would break off. They seem brittle but not quite as brittle as I though by looking at them. Next I have to use a 555 timer as a monostable vibrator. I will now be extra careful with the pins this time. Thanks again for the info.
     
  6. bertus

    Administrator

    Apr 5, 2008
    15,646
    2,345
    pfelectronicstech likes this.
  7. pfelectronicstech

    Thread Starter Member

    Jan 18, 2012
    178
    4
    Oh I like that, that makes sense. Thanks for the link.
     
  8. atferrari

    AAC Fanatic!

    Jan 6, 2004
    2,647
    759
    Yes, turned sockets are the best.

    It took me more than 3 years for the same 18F452 used intensively (very) to loose pin 21 (not surprise it is in one corner) because not always I take it out with an extractor.

    BTW, that is why I always buy not less than 3 ICs of each type thinking of those weekends where you can get good espressos but not replace the IC that had the bad idea to fail at that moment.
     
  9. CircuitZord

    Member

    Oct 8, 2012
    59
    2
    The next thing to watch out for, is to remember to turn on your PSU, remarkable how it even gets lab demonstrators still...5 people will crowd around the circuit wondering why it isn't working until someone realises there's no power.
     
  10. MrChips

    Moderator

    Oct 2, 2009
    12,429
    3,360
    I've been there, seen it all, have long list of what students will do:


    1. Power cord not plugged in
    2. Power switch not turned on
    3. Banana post pinches on insulation, not on wire
    4. Floating supply not grounded
    5. Vcc and GND not connected to IC
    6. Vcc shorted to GND
    7. IC plugged in backwards
    8. Wrong IC part number
    9. IC not straddling centre channel on breadboard
    10. IC pin curled under IC (as OP)

    and more...
     
  11. DerStrom8

    Well-Known Member

    Feb 20, 2011
    2,428
    1,328
    Hahaha, I've seen each and every one of those, and I've only been working with students at the university for a year! :D

    I've also seen a lot of issues with discrete components--diodes in backwards, diodes shorted across the supply, small 1/4 watt 10 ohm resistors connected directly across 6v, transistors placed backwards, and more :p
     
  12. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,157
    Failure to exercise due dilligence covers all the basic aw $hits.
     
Loading...