Volts ?

Discussion in 'MacBook Pro' started by hotrod351, Sep 30, 2015.

  1. hotrod351 macrumors 6502

    hotrod351

    Joined:
    Mar 3, 2007
    Location:
    Mohave Valley Arizona
    #1
    had to get another charger for my 2007 macbook pro. i did find the end of the wires were shorted out so i also ordered another cable for it. i checked the voltage output with the cable disconnected and it puts out a little under 7 volts, is that right. thought they put out 10 or better.
     
  2. Kissmyne macrumors 6502

    Kissmyne

    Joined:
    Apr 21, 2015
    #2
    If it is a Apple branded MagSafe adapter, it is a "smart" charger and does not supply full voltage when it detects that it is not plugged in to a computer, I have the same phenomena occur when I try to measure the voltage of my adapter with a voltmeter.

    Should be around 20 volts when attached..
     
  3. joe-h2o macrumors 6502a

    Joined:
    Jun 24, 2012
    #3
    The charger brick puts out about 7 V at low current when it's not under load. After the magsafe handshake, which takes a second or so, the charger switches to full DC voltage.

    They put out about 14-18 V DC at full load depending on the model.
     
  4. hotrod351 thread starter macrumors 6502

    hotrod351

    Joined:
    Mar 3, 2007
    Location:
    Mohave Valley Arizona
    #4
    well i ordered another cable for it, also have a new charger. ill see when i solder in the new cable as to how good it charges. i do understand what you mean.
     
  5. joe-h2o macrumors 6502a

    Joined:
    Jun 24, 2012
    #5
    If you replace the cable it will work just fine, assuming the brick itself is ok. Just be sure you got the right type of cable - the magsafe plug itself contains the little chip that controls the colour of the charging light and it also contains the ID that lets the MBP know what type of charger you have connected (45/60/85 W). Ideally you want to replace the cable with one from the same type of charger. At the brick end there will only be two cables to solder - positive and negative, and possibly the shield (I forget).
     
  6. hotrod351 thread starter macrumors 6502

    hotrod351

    Joined:
    Mar 3, 2007
    Location:
    Mohave Valley Arizona
  7. nebo1ss macrumors 68030

    Joined:
    Jun 2, 2010
    #7
    intrigued to know where you are getting the cable from. I have a couple of old charger where the cable failed and could never find one on an internet search.
     
  8. hotrod351 thread starter macrumors 6502

    hotrod351

    Joined:
    Mar 3, 2007
    Location:
    Mohave Valley Arizona
    #8
    amazon. if it doesnt work then amazon refunds me the total vost
     

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