question about "Network Interface" phone jack

Jul 25, 2005 2 Replies

Network Interface *Caution Disconnect plug from this jack during installation and repair of wiring. *Testing Plug working phone directly into this jack. If phone operates, fault is in wiring. If phone does not operate, call repair service.


When I opened the case, I noticed that the red and green wires (the only ones that will be actually used by the telephone itself) are also connected to a little circuit board whose most conspicuous component is a yellow cylinder-shaped object (about 3/4" long and about 3/8" diameter) with the following markings ...



250V TI 0.47 MFD +/- 10%


  • What is the purpose of this circuit board?

  • Is it really necessary? (How come the old-fashioned jacks didn't have this?)
  • What if I were to disconnect it?


Also, when I looked inside the jack itself (the hole where you would plug the phone into), I noticed there's some strange-looking gunk inside. It's clear-colored and has the consistency of rubber cement.


  • Is this something that's supposed to be there?
  • What is it used for?


Its what it says it is: the network interface. It is the point where the telephone company's wiring stops and yours starts. It is not intended to be used for a telephone jack. Also, you are not supposed to be inside the box, other than to plug in a telephone to verify your side of the wiring before calling for repair service. As far as the circuit board, why would you want to remove it?

Link to my "Computers for disabled Veterans" project website deleted after threats were telephoned to my church. Michael A. Terrell Central Florida

I give up

Perhaps electronic surge protection

Why would you want to, it ain't broke.

Yes

Corrosion control.

Carl Navarro

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