How to measure a 100/1000BASE-T transformer module ?

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  • Gabriel
    Badcaps Veteran
    • Jan 2010
    • 620
    • Norway

    #1

    How to measure a 100/1000BASE-T transformer module ?

    I have a router that all the lan ports + the wan port is dead.

    How can I test the transformer modules to see if they are working or not ?
    I have the Delta Lf9402 modules.


    Thanks
  • japlytic
    Badcaps Legend
    • Oct 2005
    • 2086
    • Australia

    #2
    Re: How to measure a 100/1000BASE-T transformer module ?

    Did the WAN port get connected to a phone line? Some people think the "internet" port is for the phone line, and many are not marked to warn people not to connect it to a phone line.
    Ethernet transformers can be a bit hard to test, considering that the windings show as shorted at DC or low frequencies. I found that fact useful in tracking down a defective network port in our new house, and the cause was a wire (used for Gigabit) missing its target on the wallplate connector.
    My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.

    Comment

    • Gabriel
      Badcaps Veteran
      • Jan 2010
      • 620
      • Norway

      #3
      Re: How to measure a 100/1000BASE-T transformer module ?

      I found this router in the garbage at work so I do not know what happend to it but it has had a hard life - https://www.badcaps.net/forum/showth...3177#post93177

      I replaced the two blown caps but the lan and wan port was still dead.
      I was up all night and removed and measured all the electrolytic caps but they were all fine. I did notice the ip101a ethernet transceiver was really hot, I will get one on ebay and see if replacing it helps.

      Comment

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