russ@silver.bacs.indiana.edu (Jeff Russ) (05/02/89)
My telephone recently started acting up. When I pick up the phone I hear a loud hum. I can still dial numbers and make connections but the hum is so loud that I can hardly hear anything. The onhook voltage is 51 volts and the offhook voltage is 6 volts. I have another phone on the same line and it does the same thing. Does this look like a phone company problem and not a problem with my wiring at home? The only things connected to the line are telephones that I bought from the phone company. There was a thunder storm with lots of lightening before I noticed the problem. I'd appreciate any suggestions as to what to check before I call the phone company. Jeff Russ russ@silver.bacs.indiana.edu BITNET: russ@iubacs
edg%bridge2.ESD.3Com.Com@ames.arc.nasa.gov (Ed Greenberg) (05/09/89)
In article <telecom-v09i0155m01@vector.dallas.tx.us> russ@silver.bacs.indiana. edu (Jeff Russ) writes: >My telephone recently started acting up. When I pick up the phone I hear >a loud hum. >... middle deleted > ... there >was a thunder storm with lots of lightening before I noticed the problem. >I'd appreciate any suggestions as to what to check before I call the phone >company. > Jeff Russ My guess is you've blown a carbon protector. This happened to my family when I was about 18 years old (15 years ago) and it was a major pain in the *ss because I had the house full of then "illegal" phones. You need to (a) unplug all the phones and other telephony equipment in the house, (b) find the demarcation point where the line enters and (c) test the line there. If it still acts up, call the telco. What's going on is this... Theres a block where the phone line enters which has two carbon inserts connected to ground. These protectors are supposed to short to ground when lightning or other transients strike. If one blows, you've got a grounding problem. This causes the hum. The carbon block will be found in the basement, garage or on the wall outside the house. It will have two screw or bolt down terminals, and two other screw covers containing the carbons. The outside wire will be connected to the two bolt-down terminals. The inside wire will also be connected to those terminals. There will also be a ground which will be grounded (or "earthed" as our friends in the UK say.) If your house is new, there will also be a modular "demarcation point" which defines where telco responsibility ends and house wiring begins. If so, unplug the demarcation jumper and plug a phone into "their" side. If it hums, call them. If it don't you've got another problem, probably a grounding problem inside the house. Good luck, and let me know if I was right. -edg -- {decwrl|sun|oliveb}!CSO.3com.com!Edward_Greenberg Ed Greenberg -or- 3Com Corporation {sun|hplabs}!bridge2!edg Mountain View, CA 415-694-2952
gentry@buita.bu.edu (Art Gentry) (05/09/89)
In article <telecom-v09i0155m01@vector.dallas.tx.us>, russ@silver.bacs. indiana.edu (Jeff Russ) writes: > My telephone recently started acting up. When I pick up the phone I hear > a loud hum. I can still dial numbers and make connections but the hum > is so loud that I can hardly hear anything. The onhook voltage is 51 volts > and the offhook voltage is 6 volts. I have another phone on the same > line and it does the same thing. Does this look like a phone company > problem and not a problem with my wiring at home? The only things connected > to the line are telephones that I bought from the phone company. There > was a thunder storm with lots of lightening before I noticed the problem. > I'd appreciate any suggestions as to what to check before I call the phone > company. Sounds suspiciously like you have a blown ground protector. This is a fuse like device in the junction box, where the telco cable comes into the building. It's purpose is to prevent excessive potential (like a lightening strike) from entering the equipment. Another possibility is a high ground on the cable, this could be either inside or outside wiring. Telco can rapidly test for a ground and tell you if the problem is theirs or yours. Odds are, since you mentioned the storm, that the protection fuse has done its job and needs to be replaced by the telco. Art