Help please in identifying this

Discussion in 'The Projects Forum' started by Lester01, May 16, 2009.

  1. Lester01

    Thread Starter New Member

    May 16, 2009
    8
    0
    This belongs to my navigation door setup in my car. A replacement would be very costly. Apparently it went after the car was jumped improperly-by me.

    Notice the burned piece on the board and the broken piece that says 200 on it. Are they two separate components or as someone else told me the 200 portion is the cap for the other part. The burned piece on the board said (15B and 14 below it). For sure 5B, not too sure on the 1 before it.

    Any ideas where I could get a replacement and further, what is it? thank you very much.
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Not a bad photo, but the problem is that there is too much flux on the board.

    Your local Wal-Mart sells 91% isopropyl alchohol by the quart in the pharmacy for a dollar or two. This is a solvent for rosin flux, but it takes awhile for the flux to dissolve.

    You can speed the process by getting some "acid brushes" from your auto supply store. These have black nylon bristles and rolled metal handles.

    Be careful with the isopropyl alchohol; it is flammable, and burns with a nearly invisible flame. It also absorbs moisture out of the atmosphere.

    Find the other half of the resistor (the item with "20" on the top). It's somewhere.

    No clue what the other item is yet.
     
  3. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    I think its a zener diode because of the ZD1 label on the left.

    Is the piece with 20 on it soldered there?
     
  4. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    ZD1 does appear to lead one to the conclusion that the component was a zener diode. It may be tough to determine what the zener voltage was though.

    hgmjr
     
  5. Lester01

    Thread Starter New Member

    May 16, 2009
    8
    0
    Thank you. Yes, the piece broken piece that says 200 on it appears to be soldered on the end of the black piece. The 'loose' piece on pictured under the board-follow the yellow lines.

    I tried using the 91%, made things worse on top of the black IC(?). The lettering is now gone. But at least I took some pics.

    Again, any ideas? Repairable?
    thanks
     
  6. Lester01

    Thread Starter New Member

    May 16, 2009
    8
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    Thank you, would I be premature in believing it was 12v as the motor it operates is a 12v motor for the door?
    thank you
     
  7. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    15B is a legitimate smd code for a 15V zener diode.

    hgmjr
     
  8. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    I wonder if the component fragment that has 200 written on it was a 200 ohm resistor that prior to the damage occuppied the site R1.

    hgmjr
     
  9. DonQ

    Active Member

    May 6, 2009
    320
    11
    That's what I was thinking. R1 was in series with ZD1, maybe just as an over-voltage protection for a 12V system. When the voltage was reversed, ZD worked as a forward biased diode (0.7V Drop). Lots of current so R1 and ZD1 both got hot. ZD1 leaked goo until R1 popped and blew itself out of its melted solder pads. One half just happened to stick to ZD1.

    R1 (200Ω) is gone! ZD1 is also probably wasted (but about a 1 in 10 chance it is still OK since most of the heat would have been in R1. Easy to check if ZD1 is blown.)

    Both parts are fairly easily found at any of a number of electronic parts suppliers. Is it OK to say company names here?
     
  10. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    If you mean the component suppliers, there is no problem mentioning the manufacturer of the parts you are considering.

    hgmjr
     
  11. Lester01

    Thread Starter New Member

    May 16, 2009
    8
    0
    Good information everyone, thank you. Did not think of R1 going south. Please, company name would be helpful. Thank you
     
  12. DonQ

    Active Member

    May 6, 2009
    320
    11
    Digikey.com is probably the first place I would try.

    You have to find a surface mount resistor with the same value and the same dimensions as the one that was there. If it is the same size, it will be the same wattage.

    With the number off of the zener, you may be able to find it directly with the search feature of the site.
     
  13. Lester01

    Thread Starter New Member

    May 16, 2009
    8
    0
    Thank you everyone,
    I chatted with the folks at Digikey.com and received the following links. I am a bit confused on the resister as I was sent 2 part numbers, one is a 20 and the other is a200. The former said that I should not worry about it as the first two digits is the most important and the last is the multiplier. Confused as other 2nd guy sent me the link to an actual 200ohm resister. My part (in the picture above has a 200 on it). The size on the 20ohm is 6mmx3mm, a but too long. The 200 is 5mmx3mm which is closer to my 4.5mmx3mm. The wattage on the first resister is 1w and the 2nd is 3/4w.

    Here are the links provided to me. I am prepared to purchase them and would appreciate some verification from an expert here to ensure they appear they would work. Thank you

    Zener Diode

    Resister one- 6mmX3mm 20

    Resister two- 5mmX3mm 200
     
  14. franzschluter

    Active Member

    Jun 1, 2009
    95
    0
    Just buy extras.. these resistors and zener diodes come in very cheap prices. The size of the resistors doesn't really matter in your case.. If it's a 1 watt or 3/4 watt won't make the lady whistle. Go for the 3/4 watt so it'll burn easier in the case a short circuit does happen again. A 1 watt resistor will be harder to burn than a 3/4 watt.

    For cleaning your board there are many PCB cleaning solutions in any electronics hardware shop.. IPA can be used but it leaves white marks.
    Take note of the polarity of the zener diode before replacing it.

    Make also sure that you solder it properly on. Do a conductance test after soldering.

    Worse case scenario is that you burn the same spot twice :D

    Regards
    Franz
     
  15. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,754
    760
    The Resistance is 20 Ohms, no doubt abt it.
    Zener is 15V if the supply is at 12V.

    I would not suggest forward biasing a zener as it will lead to destruction of it.

    Replace both parts and test. This what I would do.

    Rifaa
     
  16. Lester01

    Thread Starter New Member

    May 16, 2009
    8
    0
    Thank you, so I just wasted some money ordering the other items. So much for relying on their chat function.
    I will have to search and try to find something on my own. Thanks again.
     
  17. Lester01

    Thread Starter New Member

    May 16, 2009
    8
    0
    Just wanted to extend a thank you! Soldered both pieces on the board and my nav is back up and running perfectly. Saved me a ton of money.
    thank you
     
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