T3 time outs are usually associated with ingress on the line. I would guess your US SNR is probably dipping into the 20s with quite a few errors. They might need to check out your return levels also, once you start getting up into the 50s you could start to see some problems if the signal fluctuates throughout the day.
I have to question when you said they replaced part of the line since usually if part of a line is bad the entire piece should be replaced and not just barrel spliced together. I would have them back to dig into it some more.
Hello AstrosFan1984. I can assist with troubleshooting your internet connectivity issue. I'd like to start with polling the CMTS for real-time and historical RF signal reports from your modem. I can also check your local Node/Plant for any degradation or error reports. Please reach out to me via private message and include your full name and account primary phone number so I can access your equipment.
Here is what has happened and where we are currently.
Tech #1: replaced section of cable from pole to back of detached garage, installed 2 barrel ground blocks instead of old splitters.
Tech #2: replaced 3rd section of cable from new ground block to inside home. Found knick in this cable and claimed this was the issue and that indoor cabling would have to be worked by an electrician as not supported by comcast.
Tech #3: Changed a -7db 3 way splitter in the attic, a "clear" barrel connector, which brought the signal on the upstream link down, but raised the downstream. Installed 2 stacked attenuators to lower this down.
Here is the event log after I cleared it from tech #3: