Kitz Forum

Broadband Related => ADSL Issues => Topic started by: neil on December 03, 2020, 09:36:23 AM

Title: Fault - Possible High Resistance?
Post by: neil on December 03, 2020, 09:36:23 AM
[This topic has been created by splitting off from siofjofj's "Help With Hard to Find Fault - Possible High Resistance (https://forum.kitz.co.uk/index.php/topic,25168.0.html)" thread.]

Unfortunately you are experiencing a similar problem as before . . . There is (at least) one joint showing HR or semi-conductive tendencies.  :(

looks like there is issue with my phone set

after removing the phone set SNR back to normal
  🤔
Title: Re: Fault - Possible High Resistance?
Post by: tubaman on December 03, 2020, 10:12:12 AM
looks like there is issue with my phone set

after removing the phone set SNR back to normal
  🤔

Are you using a microfilter, and if so have you tried changing it?
 :)
Title: Re: Fault - Possible High Resistance?
Post by: neil on December 03, 2020, 10:25:54 AM
Are you using a microfilter, and if so have you tried changing it?
 :)
Yes using a microfilter and i have changed it.
other phone set is working fine
there is no cracking noise in it

Title: Re: Fault - Possible High Resistance?
Post by: burakkucat on December 03, 2020, 03:45:09 PM
You could try interchanging the telephones. I.e. Telephone number one is normally at position (a) and telephone number two is normally at position (b). Try with telephone number one at position (b) and telephone number two at position (a).
Title: Re: Fault - Possible High Resistance?
Post by: neil on December 03, 2020, 07:36:50 PM
You could try interchanging the telephones. I.e. Telephone number one is normally at position (a) and telephone number two is normally at position (b). Try with telephone number one at position (b) and telephone number two at position (a).

I tried both at same location and here is the result.
good phone from position (b) good one i guess, no noise
bad phone is from position (a) can hear noise

https://drive.google.com/drive/folders/1W4xNoikqOl6T9adhLaVmJoBMm8qfDxZS
Title: Re: Fault - Possible High Resistance?
Post by: burakkucat on December 03, 2020, 07:43:48 PM
Thank you.

Just to clarify, does the "badness" move with the telephone or does the "badness" remain associated with the socket?
Title: Re: Fault - Possible High Resistance?
Post by: neil on December 03, 2020, 08:42:23 PM
Thank you.

Just to clarify, does the "badness" move with the telephone or does the "badness" remain associated with the socket?

tested both phones at the same location.
I removed the extension and connected both phones. Also tested one by one I can only hear noise in bad phone.
Attached UPstream SNR and you can see little bit drop in SNR when phone is in use.
Title: Re: Fault - Possible High Resistance?
Post by: burakkucat on December 03, 2020, 10:40:09 PM
tested both phones at the same location.

That is a good test.

Quote
Also tested one by one I can only hear noise in bad phone.

Then I would suspect a problem with that one telephone.

Quote
Attached UPstream SNR and you can see little bit drop in SNR when phone is in use.

That is showing some degree of abnormal loading on the line when the telephone is in use. It could be caused by either a faulty telephone or a faulty splitter.
Title: Re: Fault - Possible High Resistance?
Post by: tubaman on December 04, 2020, 07:40:47 AM
...
https://drive.google.com/drive/folders/1W4xNoikqOl6T9adhLaVmJoBMm8qfDxZS

Your good phone has a cat stuck inside it - this may be your problem! When first playing it I thought it was my cat and went to look for him.  :lol:
Title: Re: Fault - Possible High Resistance?
Post by: neil on December 04, 2020, 08:00:38 AM
Your good phone has a cat stuck inside it - this may be your problem! When first playing it I thought it was my cat and went to look for him.  :lol:

bad phone also has cat in the end  :lol:
Title: Re: Fault - Possible High Resistance?
Post by: neil on December 04, 2020, 02:38:28 PM
That is a good test.

Then I would suspect a problem with that one telephone.

That is showing some degree of abnormal loading on the line when the telephone is in use. It could be caused by either a faulty telephone or a faulty splitter.

I tested good phone used at location (b) at location (a) for a day and there is no cracking noise in it. bad phone is not plugged in
modem up time is 13H 37mins
Code: [Select]
Mode: VDSL2  
Traffic Type: PTM
Status: Up
Link Power State: L0
 
  Downstream Upstream
Line Coding(Trellis): On On
SNR Margin (0.1 dB): 309 295
Attenuation (0.1 dB): 177 0
Output Power (0.1 dBm): 137 94
Attainable Rate (Kbps): 76352 40659
 
  Path 0 Path 1
  Downstream Upstream Downstream Upstream
Rate (Kbps): 23597 10742 0 0
 
B (# of bytes in Mux Data Frame): 31 31 0 0
M (# of Mux Data Frames in an RS codeword): 1 1 0 0
T (# of Mux Data Frames in an OH sub-frame): 64 64 0 0
R (# of redundancy bytes in the RS codeword): 10 2 0 0
S (# of data symbols over which the RS code word spans): 0.0431 0.0947 0.0000 0.0000
L (# of bits transmitted in each data symbol): 7792 2873 0 0
D (interleaver depth): 187 9 0 0
I (interleaver block size in bytes): 42 34 0 0
N (RS codeword size): 42 34 0 0
Delay (msec): 2 0 0 0
INP (DMT symbol): 0.50 0.00 0.00 0.00
 
OH Frames: 11793634 4588870 0 0
OH Frame Errors: 0 0 0 0
RS Words: 233696329 2071151234 0 0
RS Correctable Errors: 90 0 0 0
RS Uncorrectable Errors: 0 0 0 0
 
HEC Errors: 0 0 0 0
OCD Errors: 0 0 0 0
LCD Errors: 0 0 0 0
Total Cells: 2224097187 0 0 0
Data Cells: 76776996 0 0 0
Bit Errors: 0 0 0 0
 
Total ES: 0 0  
Total SES: 0 0
Total UAS: 30 30
Title: Re: Fault - Possible High Resistance?
Post by: burakkucat on December 04, 2020, 05:32:36 PM
I think it is fairly conclusive that, from the result of your tests, you have shown the problem is due to that one particular telephone.
Title: Re: Fault - Possible High Resistance?
Post by: tubaman on December 04, 2020, 05:52:04 PM
I think it is fairly conclusive that, from the result of your tests, you have shown the problem is due to that one particular telephone.

Agree.
Assume you have rescued the cat from the other one too... ;D
Title: Re: Fault - Possible High Resistance?
Post by: neil on December 08, 2020, 03:20:46 PM
most probably this telephone hook 6 pin switch was the culprit
because when i was used to push the handset button to reset there was so much cracking noise in it
I have replaced it hopefully it is fixed now, no noise so far
Title: Re: Fault - Possible High Resistance?
Post by: Alex Atkin UK on December 08, 2020, 03:28:48 PM
Strange though, as surely the filter should block any noise from making it onto the DSL frequencies.  I wonder if it was somehow creating a short circuit?
Title: Re: Fault - Possible High Resistance?
Post by: burakkucat on December 08, 2020, 05:56:45 PM
Strange though, as surely the filter should block any noise from making it onto the DSL frequencies.  I wonder if it was somehow creating a short circuit?

It's difficult to say with any degree of certainty. But, as neil has now replaced the component and the fault is no longer present, the result is good enough for me.  :)
Title: Re: Fault - Possible High Resistance?
Post by: neil on December 09, 2020, 05:36:27 PM
It's difficult to say with any degree of certainty. But, as neil has now replaced the component and the fault is no longer present, the result is good enough for me.  :)

yes phone is working fine and no longer any cracking noise  :graduate:
Title: Re: Fault - Possible High Resistance?
Post by: neil on January 21, 2021, 12:10:57 PM
again SNR dropping on upstream and there is no noise in telephone.
can it be a back end issue?

Title: Re: Fault - Possible High Resistance?
Post by: neil on January 21, 2021, 12:19:06 PM
i was away and i left dsl stats running. I came back and saw it. No noise in telephone line when i saw the stats. Don't know if there was any noise when SNR dropped
Title: Re: Fault - Possible High Resistance?
Post by: burakkucat on January 21, 2021, 04:34:33 PM
Those two plots are indicative of one (or more) defective joint(s). The problem is finding where it is (or they are) and then making a lasting fix.