trying to repair my car radio, need some help identifying a surface mount component

Discussion in 'General Electronics Chat' started by sedemdeh, Oct 8, 2007.

  1. sedemdeh

    Thread Starter Member

    Nov 18, 2004
    11
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    my camera is busted but I not sure if I could have gotten a clear pic anyway..
    the component in question has the markings as displayed in the pic..
    I'm not sure if its a transistor or something else and I've tried to search but I don't have much to go on..

    any help would be great, I just need to find something comparable
    [​IMG]
     
  2. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
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    It is an SMD component, but I can't really guess what it is. Besides the markings, can you see any sequence of characters?
     
  3. sedemdeh

    Thread Starter Member

    Nov 18, 2004
    11
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    that is all that was on it, nothing else
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
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    The package could be for an SMT transistor, but there is no way to tell what polarity or kind from the illo.
     
  5. sedemdeh

    Thread Starter Member

    Nov 18, 2004
    11
    0
    the circuit controls the lcd display on the radio. the leg on the side that looks like a Q is positive, and I can get the display to work by jumping that positive leg to the center leg..
    My problem is that when that is done the radio draw more current even when turned off and could possibly drain the battery..
     
  6. lightingman

    Senior Member

    Apr 19, 2007
    374
    22
    This device, as far as I can tell is an MMBT5088 If the marking is 1Q. NPN, vce = 30v.Hope this helps.....Daniel.
     
  7. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    good call on lightingman's part.

    If you can't find an MMBT5088, you might be able to use a 2N5088; that's the same transistor in a TO-92 case. I had to do that when I was visiting my folks in July for a week; couldn't find a SMT version of a 2n3904 to fix their cordless phone locally, and didn't have time to wait for one to be delivered. Took some careful lead bending and trimming to make it work, but work it did.
     
  8. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
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    You are the man!:D

    Now serioulsly, you can you tell exacly the type of the trnsistor by readind the marking "1Q"? Is there a table for these markings?
     
  9. SgtWookie

    Expert

    Jul 17, 2007
    22,182
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    There are quite a few tables out there. In the past, standardization of markings was a huge problem, but it's getting better.

    Here is a very useful site:
    http://www.educypedia.be/electronics/datacomponent.htm

    You'll still have "rummaging around" to do, but at least you'll have lots of stuff to look at ;)

    One of the really nice things about that site is that it'll give non-ROHS compliant equivalents (that is, parts that may contain lead and other elements heinous to the environment) if available - very handy for those with well-seasoned "treasure boxes"

    For example, a quick check shows that MPSA18 is a non-ROHS compliant but otherwise equivalent replacement for the OP's part.
     
  10. lightingman

    Senior Member

    Apr 19, 2007
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  11. sedemdeh

    Thread Starter Member

    Nov 18, 2004
    11
    0
    thanks for all the assistance guys, hopefully I can get this radio working properly again
     
  12. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Nah, you didn't cheat.

    85% of the battle is just knowing where in the heck to look something up! ;)
     
  13. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
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    The other 15% is remembering where I put that darn whatsis!!
     
  14. sedemdeh

    Thread Starter Member

    Nov 18, 2004
    11
    0
    ok where can I get this thing without paying for 50-100 (2N5088 that is)
     
  15. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
    10
    Very good resource! You should put this in the "Electronic Resources" section, if you didn't.

    I can't open the link! I think it is malformed. I think this is the link:
    www.tkb-4u.com/code/smdcode/indexsmdcode.php

    Everyone cheats, but of course, some cheat more (like Bill MS).
     
  16. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    Try online auctions. The big one has at least three vendors currently offering 2N5088s.
     
  17. mtwire

    New Member

    Jun 26, 2008
    1
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