US Land Line Telephone Terminal Block Internal Connections

You been spying in my plant? This looks just like it...

I'm not sure, but I think all four "forks" in a row are interconnected as a single piece of metal. (If I don't forget, I can ohm it out tomorrow.)

Here is some information http://en.wikipedia.org/wiki/66_block. The link makes reference to tip and ring http://en.wikipedia.org/wiki/Tip_and_ring.

If you do not have backlights on your phones and if you don't have two "lines" coming in on one cable then (if I recall correctly) you will only be using the red and green wires in the middle of the modular cable. With a multimeter TIP should read about +48VDC with respect to RING.

The first link states that phone company TIP (more positive) will be on the upper left terminal of your Type 66 block. Phone company ring (more negative) will be on the far left terminal of the row below it. Bridging clips go horizontally across the middle gap. Your home/office TIP will be row 1 far right. Your home/office RING will be row 2 far right.

Often the TIP, RING pairs continue down from there.

The phone company uses ground and negative. That is why I stated "more positive" and "more negative" with your multimeter.

If you "oops" the phone company might detect the short circuit, start a timer and disconnect your line until the timer expires. The phone company knows exactly how long each person will wait until they give up and the timer will be set for one minute longer.

No dial tone used to mean the phone was off the hook somewhere in the house,The second line you had might have been the Main line.

I recently got one of these blocks installed at my house, and for the first month or so, all was good. One day, no dial tone. Traced the problem back to this terminal block. The wires were all "stabbed" down well, but at least one of them was not making good contact. I pulled all wires from the block, pinched the "forks" together a bit tighter, and re-stabbed the wires, it's been good now for about half a year.

As to your question, I "think" each column of the 4 is connected all the way from top to bottom, so you basically have 4 circuits, one for each color, with 12 tap points. Not sure why someone would mix colors, doesn't seem like a good thing to do. Perhaps someone had an issue with a particular pair, and decided to use different colors, which would mean using a different pair at the far end as well. If it were me, I'd probably start over at the distribution block with all the colors in the proper column, and then check the far ends, making corrections there as necessary. I hate it when someone doesn't follow the "standard" for the sake of expediency!

Tom D.

The non-uniformity of colors seems odd to me as well.

Going on your statement that nothing has changed or been added to the system, try removing one pair (cable) at a time. Check for a dial tone as each pair is removed. Again, do this one at a time replacing each pair (cable) as you go along.

Buy yourself a punch down tool to re-install each pair (cable)

Punch down tools go for about $20 USD. Here is a link.

Good Luck!

This block is actually 4 rows of 12 for use with 1 line or 2 or 1 phone line and 1 for a separate fax line. The main incoming line usually only uses 2 of these rows, 1 for the ringer or tone and the other for voice and data.(IE:Call Display). These type of pinch connecters as I call them were disigned so the wire could be connected to them without the need to bare the wire(Big Time Saver) but sometimes the plastic covering on the wire does not break clean when installed and a vibration or just time( maybe a small bit of corrosion) can cause a disconnection for no apparent reason. If you had more wall jacks than 2 rows could provide(11) you would need to use 2 jumper wires to activate the other 2 rows for that line. (Each wall jack will have it's own wire running back to this Block). Normally the other 2 rows are used for a second line or Fax, or internet from your phone company. If for some reason you needed more space they would simply install another block.

Rescue

Tonight I finally discovered the culprit - a wall-jack-to-phone cable that had lain on a baseboard heater. The insulation cooked, cracked and finally broke, exposing the wires which would intermittently short or not.

It was the ONLY cable I did not disconnect during all the hours of troubleshooting because it was the one line I wanted connected (the one I would test for a dial tone) and the section of it that I could see was just fine. The burnt part was hidden from sight.

But at least I finally found it.

Thank you all for your help with the 66 terminal block.

I have found from this that a small exposure to the wire can confuse the whole terminal connections.