Cell Phone Sim tray replacement / pad replacement problem

Discussion in 'The Projects Forum' started by jarazmek, Apr 28, 2014.

  1. jarazmek

    Thread Starter New Member

    Apr 26, 2014
    5
    0
    Hello All About Circuits,

    I have searched high and low in the vast "Internets" and I have yet to find a clear GO or NO GO answer to my question / problem. So I turn to the experts here in hope of someone shedding some light on my issue. I have some solder experience and a small amount of 2M, I received a motherboard from a cellphone that had the pins from the SIM tray broken off. I thought it would be no big deal to take a try at removing the bad and install the new. The problem is the sim tray holder, Without a schematic I don't know if the two pads that I lifted are a ground of sorts or just an anchor point to hold it in place. The green circles are the feet of the sim try holder with the lifted pads still attached. The red circles are where the pads use to connect. So the question is can I just use a conductive tape or a silver trace paint and be safe? Should I do a full prep on the surface and try to find good clean copper? I was told that the black meant it was good and I should just drop a new pad in the place of the old one and carry on. I have never pulled just a pad, usually I would see a trace... Even under magnification I can not see anything that looks like a trace. So should I use a conductive tape and clean both sides and re-attach? should I lay a new pad in the place of the old one and carry on, or do you think this is just an anchor point? Any help would be great and I thank you in advance.

    :confused:

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    Last edited: Apr 28, 2014
  2. Ramussons

    Active Member

    May 3, 2013
    557
    92
    They are both "anchor" points. Connection to the SIM is by direct contact pins against the SIM itself.

    Ramesh
     
    jarazmek likes this.
  3. jarazmek

    Thread Starter New Member

    Apr 26, 2014
    5
    0
    Thank you for the fast reply, it was killing me to think I destroyed a 500 dollar board. I thought that maybe it could be some sort of ground for the sim cage, I am aware of the sim card contacts and how they function. but an anchor just seems logical due to the size and position. Thank you.
     
  4. jarazmek

    Thread Starter New Member

    Apr 26, 2014
    5
    0
    After some cleaning I was able to get better pictures... I think I may be dealing with a ground, I see multiple copper traces at the edge of the removed pads.
     
  5. jarazmek

    Thread Starter New Member

    Apr 26, 2014
    5
    0
  6. jarazmek

    Thread Starter New Member

    Apr 26, 2014
    5
    0
    So do you think I could use a conductive paint to fix this? Should I use a conductive tape and reattach the pads that came off? Thank again for you help everyone.
     
  7. Ramussons

    Active Member

    May 3, 2013
    557
    92
    I don't think its critical. Pay attention to the mechanical fit rather than the electrical.

    Ramesh
     
  8. enggricha

    Member

    May 17, 2014
    62
    1
    they might have been connected to ground, but as ramussons said pay attention to the mechanical fit, because all the necessary contacts are on the sim card itself.
     
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