Constant T3 and T4 Timeout

[JimSiem]

Starting in late June, my internet would continually drop connection. I first called Xfinity tech support on June 30th. They finally sent a tech to my house sometime early in July, and he didn't find any smoking gun. Since I still had the issue, I bought a new modem, and that wasn't the fix either. I've called tech support countless times, and just get read the same script, now saying they can't send any technician out due to the coronavirus. I've seen many people in my area posting on facebook with the same issues. Unfortunately, there is no way to contact my local comcast office to tell them about this. Upon looking at the modem errors, I saw every time it drops connection, it shows the same timeouts.  I will attach image links to the errors from two different days, as well as a picture of the channels. Any help would be greatly appreciated. Thank you.

https://imgur.com/a/okwG9df

[EG]

The upstream power is almost out of spec and it may be intermittently fluctuating even higher to out of spec levels. The downstream power is on the low / weak side as well. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

[JimSiem]

Thank you very much for your helpful reply. When the tech came out in early July, he replaced the only splitter in my house that I'm aware of. The line comes off the box on the street to a plastic box mounted on the house, then up to the attic where it hits the splitter, then to my office. While testing he said the signal from the street was strong, and said the same at the modem. Seeing everyone in my area with the same issue is making me suspect there is a bigger problem at hand. Do you have a favorite brand / model of splitter? Thank you again for your reply, it is greatly appreciated.

[EG]

Quite welcome ! 

Here are some quality brand splitters that Comcast actually uses in different market areas;

Antronix CMC2002H 2-Way Splitter: http://www.amazon.com/Antronix-CMC2002H-2-Way-Splitter/dp/B001E4OH1E

Regal 2 WAY 1 GHZ Splitter: http://www.amazon.com/DIG702867-Regal-WAY-GHZ-SPLITTER/dp/B0018BQMUM/ref=sr_1_2?s=electronics&ie=UTF...

Extreme Broadband BDS102H 2-Way Digital Coax Splitter: http://www.amazon.com/EXTREME-DIGITAL-PERFORMANCE-CABLE-SPLITTER/dp/B007YV0UQW

Holland 2-way horizontal splitter 5-1000 MHz with ground.http://www.3starinc.com/holland_2-way_horizontal_splitter_5-1000_mhz-w-ground.html

Sv-2g 2-way Splitter 5-1000mhz: http://www.amazon.com/Sv-2g-2-way-Splitter-5-1000mhz-Sv2g/dp/B003TH36CK

The splitter may not be the problem but it's worth a try.

Perhaps another tech visit would be best. Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home.
Good luck !

[JimSiem]

I appreciate all the links for splitter and the advice. Upon further investigation, there actually are no splitters in my house. In the attic is just  a barrel connection, same with the box outside. I saw another thread on facebook yesterday filled with locals complaining of service issues. I guess the only thing to do now is wait for my local office to reopen. Still dealing with constant signal drops. Pretty frustrating!