April 28, 2008
KTS trouble (boring!!!)
Got a trouble ticket Friday for the Hawthorne Central Office -- the carrier phones are not ringing. Precisely just the KTS carrier phones, the parallel Nortel/Spectralink wireless phones work fine. The problem is definitely in the 1A2 Key Telephone System. You know those old business telephones with the buttons that would light up, dating from the '40's or '50's?? We still use them.
Anyhow, poke around and see that the trouble is something on the ringing pair that is dragging the voltage down.
The first two pictures are pink boards -- the KTS equipment for the first two of the six carrier lines. The top pair is the incoming dial tone. Usually there is just the one jumper on the top pair, but sometimes a line bell will be tie there. Or, in this case, a jumper to parallel the dial tone over to the Nortel system. Second pair is the talk pair going to the KTS telephones. Third is the A-A1 control leads. Fourth is the Lamp-Lamp ground leads. Fifth, bottom, is the B-R1 leads which provide ringing to the phones. (Ringing on KTS is optional and extra cost.) Since all the carrier lines appear on all of the carrier phones, all the bells leads of all six carrier lines are tie to each other and to every carrier phone that rings.
So I start with '08, lift the cross connects, call the line and check the voltage. Good. Punch down a pair, good. Another, still good. Punch the last pair, sure 'nuff, kills the ringing. Trace to the B-R1 of the '09 line, which has three more jumpers on it. We could be looking at a hour or two tracing jumpers here. OR the gods might just smile upon us. Pull a jumper off and the voltage jumps up to normal. AND that jumper goes to a floor cable rather than to another line. (third picture, the 25 pairs of floor cable #63.)
Ah.... But where does that cable go? This installation predates OCS -- there is no drawing of where on the floor each cable goes. However, I have the bell lead lifted -- therefor if the phone rings it is not the phone I'm looking for. Find cable 63 hanging from the cable racks down behind the desks in the frame/carrier admin area. It goes to one of the big boxes that allow you to attach two 75-pair phone cables to one 75 pair cable from the KTS equipment. Pull cables to find the bad one (phones ring), replace and trace. (phones stop ringing) It goes to a CPC, a smaller 25 pair adapter to connect two phones to one cable. Pull the feed cable, phones ring. Pull a phone cable, replace feed cable, ringing stops. BUT..... the lighting is poor near the floor and I thought I saw a flash in the CPC. Pull the other phone cable -- all I have is the feed cable and the CPC. No bells. Pull apart, bells. Connect, no bells. Separate, bells. HEY!! It's a bad CPC. A first! (Hence the blog entry.)
Wingo ripped it apart and on the backside, the protected side, something got across the traces and caused a bit of arc'ing. Cute.
Posted by Paladin at April 28, 2008 09:16 PM