help to identify component

Discussion in 'General Electronics Chat' started by montarbo, May 6, 2014.

  1. montarbo

    Thread Starter New Member

    May 5, 2014
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    Dear community
    Can anyone help identifying this component encircled in red and give info about it, datasheet may be?
     
  2. pwdixon

    Member

    Oct 11, 2012
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    Last edited: May 6, 2014
  3. montarbo

    Thread Starter New Member

    May 5, 2014
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    Thanks for reply. Very good links, thanks again.

    Would make sense according to little tables but in general that explanation indicates three number where as the third is the multiplier and j would stand for saturation. As of the picture indicate 1000j not 102j??

    Well shall say its a capacitor, is it one with polarity or without? polarity indicator in such case?
     
  4. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Look at the PIC pinout and see what the closest pins are for. It is a 1000 KHz (1 MHz) crystal or ceramic resonator.

    ak
     
  5. montarbo

    Thread Starter New Member

    May 5, 2014
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    Thanks again.

    I thought that too and I think its a Murata CSB1000j but I wasn't sure.

    Does these go bad?
    As you can see its a car FOB ( brand CARGARD ) board. First time defective revealed the right leg solder was broken, re-soldering made it work for a few months, now defective again.
     
  6. montarbo

    Thread Starter New Member

    May 5, 2014
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    According to datasheet of the
    PIC16C54C
    the legs 15 and 16 are the osci/CLKIN-OUT which indeed connects to the resonator respectively.

    Does this mean its replaceable with oscillator, where as to get to same working frequency it need one with 1.5- 2 MHz. Or it must be a resonator given if its gone bad?
     
  7. alfacliff

    Well-Known Member

    Dec 13, 2013
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    if its a 1000 kHz (1mHz) crystal, hold the fob near an am radio tuned to 1000kHz and listen for the signal. if its working, it should have a signal near 1000 kHz.
     
  8. montarbo

    Thread Starter New Member

    May 5, 2014
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    Wish I had an AM radio.
    The FOB had a small flat speaker ( buzzer ) which used to buzz when working, it doesn't have any live signs now. Not a battery issue, no dirt ...etc. Would've been great having the schem for this little fella.
     
  9. wayneh

    Expert

    Sep 9, 2010
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    Are you kidding? Every car on the road has one. I have another half dozen in my house; clock radios, stereo systems, on and on.
     
  10. montarbo

    Thread Starter New Member

    May 5, 2014
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    Its been long since i had one of those. As for car radio mine came with only FM. Will ask some friends.
     
  11. ErnieHorning

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    Apr 17, 2014
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  12. montarbo

    Thread Starter New Member

    May 5, 2014
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    Switched the one in the second FOB, worked fine. There was the culprit but how on earth does these goes bad. Ordered one already.

    Thanks everyone for help.
     
  13. ian field

    Distinguished Member

    Oct 27, 2012
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    The ceramic resonators tend to stop working if you clean the board in an ultrasonic cleaner. Otherwise, failure is relatively rare - but not entirely unknown.

    The oscillator pins on a MCU usually bring out the input and output terminals of a CMOS inverter - the signal on the output side pin should be easy to scope, it should be more or less a sinewave as there's usually a resistor biasing the inverter into linear region.
     
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  14. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    It's a 1000 kHz ceramic resonator for sure, I have many here in different sizes.

    I will disagree with Ian Field about failure being rare though. ;)

    We used to replace a couple a week in TV and VCR remote controls, they stop working after shock damage (dropped remote). Most I have seen marked 455 or 455kHz.
     
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  15. ErnieHorning

    Member

    Apr 17, 2014
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    Ceramic resonators are actually more tolerant of shock and vibration than quartz crystal. What kills a resonator is age. They drift over time and your tuned circuit will no longer oscillate at the correct frequency.

    Ceramic resonators are used where cost is a greater desired rather than the actual frequency, just that it oscillates somewhere around a particular frequency. In fact, I bet if you could get an oscilloscope on it, it’s still osculating. Because it’s out of tune, the level is too low of a voltage for the micro’s internal oscillator circuit.
     
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  16. montarbo

    Thread Starter New Member

    May 5, 2014
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    Wow, great answers.

    Stopped at an auto service and got one complete PCB for free but its working one. Switched the resonator on mine and worked like charm. Did it just to have two fob in hands, in case of dysfunction of the other. That seemed much easier than trying to recode the free one. Otherwise expecting delivery of new ones in a week. Think i'll stick to this used one so long it keeps functional.
     
  17. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    Good point, but I don't think was the case with the TV and VCR remotes.

    The resonator there is used to clock the micro, which generates the RC code pulses. Even a large freq change of a few percent would probably not matter, and definitely not a tiny change in freq. And customers often reported a drop incident too. :)
     
  18. montarbo

    Thread Starter New Member

    May 5, 2014
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    I actually did drop my keychain including the fob a bunch of times.
     
  19. ian field

    Distinguished Member

    Oct 27, 2012
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    The rooms where people watch TV are usually carpeted, so dropping the remote doesn't often damage the resonator.

    In my TV servicing days I frequently had to clean remote PCBs after drink spillages - it was an absolute rule; remove the resonator before putting the board in the ultrasonic cleaner.
     
  20. ErnieHorning

    Member

    Apr 17, 2014
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    If they were lucky, it was only water, tea, coffee or club soda. Simply drying off the board and wit was back in business. If it was something like Mountain Dew, it would remove the gold plating on the contacts within 24 hours. I was still able resurrect one by cleaning the contacts with and eraser down to the bare copper and then covering them with some lite electronic oil. A cheap recovery for one that would normally be thrown away.
     
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