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Crowdog72
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1st Reply

11 Messages

Sunday, November 5th, 2023 8:49 PM

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Updated Modem from SB6190 to S33...line noise better but still bad

Hello,

I updated my modem and switched to our second coax line (leading from the box to our network closet) after seeing increased line noise over the past few months.  The line noise is better but the QFDM PLC line shows a high uncorrectable count.  Not sure what's going on.  Our speed should be gigabit but we are dropping down to the 200's or less sometimes.  None of this was an issue until we switched to gigabit about seven months back.  Please help.  Not sure if it's me or Comcast.

Question

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Updated 

1 year ago

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0

flatlander3

Problem Solver

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1.5K Messages

2 years ago

2nd coax line?

Is there a coax splitter in the mix there?   A lot of them are also 4dB attenuators (reduces signal power), and you're pretty weak on signal power.  Looks frequency dependent too, so that also indicates something hanging off your coax that isn't helping you out any.

Can you try a clean run directly to where your service enters your residence for a test (no splitters)?  See what the signal table looks like then, if you can get the spread on signal power a bit more even, and if there is any improvement in the OFDM PLC?  

That may not be entirely the problem, but starting out with some head room on signal power is desirable. 

5

Crowdog72

11 Messages

The second line is also in the box but neither line has a splitter on it.  COMCAST is telling me to run a whole new line but there are no splitters from the house to the back of the modem.  It seems coincidental that this started when I upgraded services.  I'm going to check with my neighbor to see if he is also having line noise issues....just in case.  

2 years ago

0

Crowdog72

11 Messages

Sorry, that is a good idea too.  I will take my modem to the box to see what happens to it there.

2 years ago

0

flatlander3

Problem Solver

 • 

1.5K Messages

@Crowdog72​  Perfect.  That will tell you if the coax from the house to the box is bad.  Good idea.

2 years ago

0

Crowdog72

11 Messages

I saw that the outside line was good.  I checked my cable route to the box.  I can see whoever ran the cables squished them through some tight holes.  The both look bent pretty bad.  I am surprised they weren't bad years ago.  I am going to have to run a new line.  Any thoughts on a good name brand for quad shield RG6??

1 year ago

0

XfinityKei

Official Employee

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1.5K Messages

Hi @Crowdog72 Have you had the opportunity to run that new line? I would like to look more at your network to help. Can you please direct message me your first and last name along with your full service address so that I can assist you further?
Here's the detailed steps to direct message us:
• Click "Sign In" if necessary
• Click the "Direct Message” icon (upper right corner of this page)
• Click the "New message" (pencil and paper) icon
• Type "Xfinity Support" in the to line and select "Xfinity Support" from the drop-down list
• Type your message in the text area near the bottom of the window
• Press Enter to send your message

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1 year ago

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