I've had 3 tech visits in last 5 days. Each new Tech has no idea about the history of what the other Techs did during prior visits. Each Tech does the same routine 1) repace splitter, 2) replace connectors at end of connection cables.
Issue is frequent internet drops. Downstream locks with ~5 to 6 dB per channel (within range) and SNR in low 40's. Upstream will show random "locks" to sometimes 1, sometimes 5, sometimes 2-4 channels. Upstream power usually in high 40's to low 50's. Problem occured with XB7 modem and a newly purchased CM1150v modem.
How do I get this escalated to someone who won't show up at the house blind each time they come??
The low fifties is too high / out of spec. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels. Something intermittent is going on with lines somewhere. Here so stuff that you can try but it may not apply. If not, you'll need a tech out again....
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.
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 with it !
I was having the same issues as you. Any time my CM1150V's upstream was over over 50 (really anything over 48), my modem's log would have so many T3 errors, which would cause my internet to stop working. I bypassed the splitter and connected straight into the tap on the side of the house. My modem's upstream were at 46, and I didn't have anything in my logs for an entire day. I added the splitter back since I need it for cable, and immediately I had consistant T3 errors. The Comcast techs didn't care about the upstream levels coming in being on the high side b/c their technically w/in Comcast's specs so I purchased a Channel Vision C-0300 Return Path Amplifier, which immediately dropped my upstream into spec. My internet has been fine so far. If you do go that route, I'd suggest putting it right next to your modem and on the longest cable run. The amp is supposed to drop your signal by -15. Good luck getting Comcast to fix your upstream issues.
FWIW. The goal is to reduce the amount of overall line attenuation in conventional ways. If more work on the line / hardware doesn't improve anything, then an amp with active return may be tried / needed. But amps are to be used only as a last resort (band-aid) fix as sometimes they can actually make things worse (garbage in equals even more garbage out). It's usually best to get a tech out to determine what is needed to properly balance the line.