Hi,
I have a very strange problem in my parents home old telephone line that goes from the first floor to the second one.
It's a simple cable pair, as the telephone on the second floor stopped working I began troubleshooting with a multimeter thinking it could be some kind of short.
I disconnected the cable on the first floor and measure the continuity thinking i will get open circuit if it was not a short, i was getting some 20Mohms in resistance no matter the order of the leads and if i used the diode mode i got open circuit in one position and if i swapped the leads i got a "diode" which was super strange.
I though the telephone itself got some internal resistance/diode or other component so i disconnected the second floor too, having now, what i though as a disconnected pair of conductors but here i got the most strange measure i ever saw in my life.
If i connect the multimeter in diode mode, now i get as expected open circuit no matter the order of the leads, but in resistance mode in one position i get open circuit but in the other i get 1Mohm, i'm without words to explain this, has anybody have an idea!!!!
Thanks.