Help on this F321!!!!!

Discussion in 'The Projects Forum' started by bolle, Aug 12, 2013.

  1. bolle

    Thread Starter New Member

    Aug 11, 2013
    3
    0
    Hi I need help on this component attached is a picture, it only says F321 on it and I need one asap or a replacement one.Need help on where I can get one or what else to replace with.
     
  2. wayneh

    Expert

    Sep 9, 2010
    12,148
    3,058
    If you don't know what it is, how do you know you need a new one?
     
  3. bolle

    Thread Starter New Member

    Aug 11, 2013
    3
    0
    There is two of them and the one is blown
     
  4. Ramussons

    Active Member

    May 3, 2013
    557
    92
    What is the unit? A few more photographs of the full board will be helpful.

    Ramesh
     
  5. WBahn

    Moderator

    Mar 31, 2012
    17,767
    4,801
    On smaller parts, manufacturers often don't put the part numbers (or even anything at all!). That makes identifying them without a schematic and/or bill of materials virtually impossible.

    You say that there are two of them and that one of them is blown. How do you know this? What is it supposed to do and what is it really doing? Knowing how you made this determination may give someone a clue as to what it is.

    Can you determine, to any degree, what this component's apparent role in the circuit is? Again, if you know enough to tell that this specific component is bad, then you probably have some idea of what it is or does.

    The fact that it is designated "U3" may (emphasis on "may") mean that it is some kind of an IC (as opposed to a transistor or some other component that is more typically designated with something other than "U").
     
  6. mitko89

    Member

    Sep 20, 2012
    123
    19
    Looks like a Voltage regulator to me. Judging from it's size its for some relatively small current, 100mA or something. Capacitors and inductance nearby, maybe a buck converter?
     
  7. sheldons

    Active Member

    Oct 26, 2011
    616
    101
    post make and model-theres a magical thing that will happen called the appearance of the relevant service manual which has things like diagrams-pictures and parts lists in them.....
     
  8. bolle

    Thread Starter New Member

    Aug 11, 2013
    3
    0
    It is a vw golf doudle dinn dvd/gps radio, the ic is on the back of the lcd main board. I treid searching it and came up with nothing so if anyone can please help me on this.
    I had someone looked at it that fixes radios but no luck with finding this part here, the people who make these radios is in china called Shenzhen and they also can not help me.

    On the PCB it says VOLKSWAGEN-MAGOTAN-GPS-TFT.PCB VER1.3 2012/4/26
     
  9. Ramussons

    Active Member

    May 3, 2013
    557
    92
    Can you give a little more info by tracing the tracks to this component, connected components, .... That will some idea of what this could be.

    Ramesh
     
  10. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    It has an inductor and caps connected by short thick tracks, so it's most likely to be a switching regulator or some type.

    Try googling for "5-pin SMD switching regulator" there should be a few hits, then get their pinouts and compare to the one you have.

    Also if you have a working one you can check voltages or 'scope waveforms on its pins.
     
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