Modem: Slow Download Speeds Motorola 7420

DWD1961

[H]ard|Gawd
Joined
Nov 30, 2019
Messages
1,235
Motorola 7420
Win 11

All of the sudden, I'm getting 4-5Mbps. I can usually max out around 120Mbps, but I've really felt the slow down since Saturday night. As usual, Comcast says everything on their end is perfect, but didn't send out a tech yet.

Modem.png
 

AgrFan

[H]ard DCOTM x2
Joined
Sep 29, 2007
Messages
619
Looks like a signal issue. Channels 4, 14-15 are out of spec. SNR should be in the 40s. Channels 2-3 are offline.

Have you tried power-cycling the modem?
 

DWD1961

[H]ard|Gawd
Joined
Nov 30, 2019
Messages
1,235
Looks like a signal issue. Channels 4, 14-15 are out of spec. SNR should be in the 40s. Channels 2-3 are offline.

Have you tried power-cycling the modem?
Tried power cycle and reset. I live in a duplex that shares the connection to the street with my neighbor. Just one coax comes in from the underground street connection and serves both of us. She said her speeds are fine. I went to the ISP office and they ran a test to my house and said everything looked fine. About 6 months ago we had our entire line replaced because the office said they were seeing tons of ingress and it was to a point where the connection was dropping. They cleaned up the OLD cable (1961 house), removed a bunch of old line and splitters, and put all connections inside of a weather box. Tested and clean 100%.

I have a Motorola tech working with me now. I bought a Motorola modem in Sep of 2019 and it started dropping connections and was giving me 10Mbps download at one year old. The Motorola tech diagnosed it and said it ws teh modem. he as right. I bought the one I have now in Nov. 2020 and have had no problem with it, until now and I don;t know if it is the ISP or the modem, yet. I have a sneaking suspicion this one went bad too. If it is, and they send out a new one, fine, but I'm not buying MotoTrash anymore. The first one was discontinued, so they just credited me back the money.

The 7420 is not discontinued, however.
 

DWD1961

[H]ard|Gawd
Joined
Nov 30, 2019
Messages
1,235
Looks like a signal issue. Channels 4, 14-15 are out of spec. SNR should be in the 40s. Channels 2-3 are offline.

Have you tried power-cycling the modem?
Motorola tech support said pretty much the same thing, and said it was on the ISP side. Comcast is coming today. I'll post back. I have a intuition they are not going to find anything. I hope I'm wrong.
 

DWD1961

[H]ard|Gawd
Joined
Nov 30, 2019
Messages
1,235
Motorola tech support said pretty much the same thing, and said it was on the ISP side. Comcast is coming today. I'll post back. I have a intuition they are not going to find anything. I hope I'm wrong.

It was a bad piece of coax, about 10' long between a line connector under our house to the modem. I just fed the new coax to the tech outside, and bam, good to go. We both inspected the old piece of coax, and there was no physical damage. Anyone have any ideas why a perfectly good piece of coax would suddenly go bad? I was thinking maybe there was a pinhole in the protective coating and the copper finally oxidized, but that seems pretty far out. Tech said he had no idea and that he had never seen a bad piece of coax like that without any visible damage.

Screenshot 2022-08-31 160957.png
 

toast0

[H]ard|Gawd
Joined
Jan 26, 2010
Messages
1,991
It was a bad piece of coax, about 10' long between a line connector under our house to the modem. I just fed the new coax to the tech outside, and bam, good to go. We both inspected the old piece of coax, and there was no physical damage. Anyone have any ideas why a perfectly good piece of coax would suddenly go bad? I was thinking maybe there was a pinhole in the protective coating and the copper finally oxidized, but that seems pretty far out. Tech said he had no idea and that he had never seen a bad piece of coax like that without any visible damage.

Well, glad it's fixed. If you carefully remove the jacket, there might be something apparent underneath? carefully remove the layers until you're at the chewy center, and maybe something will become obvious? Your really bad channels were all in 500Mhz vs mostly good channels in 800Mhz, so that's a clue an RF oriented person might understand, but not me ;)
 

TheSlySyl

2[H]4U
Joined
May 30, 2018
Messages
2,271
Glad you got it figured out. That level of correctables/uncorrectables was ridiculous.
 

Vengance_01

Supreme [H]ardness
Joined
Dec 23, 2001
Messages
6,775
Wow good service from Comcast who would have thunked it 🤣 good job to OP figuring it out. My guess the cable went bad due to elements... Blame climate change
 
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