I see one image has been dropped and I see no way to access/edit my original post so I’ll insert the channels image that concerned me, In this image 33 & 34 concerned me. In my original post I mentioned what channel 33 was on an original boot. The original boot for channel 33 was this:

Channel 33 on a fresh boot was 3.7dBmV  40.5dB 123553490  519

you have errors in the line and the logs. 

Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
If you can, simply connect the modem right where the coax comes into the home. This prevents wiring in the home from being the issue. And some ISP’s charge if the wiring issue is in the home. So this helps prevent this.

I have this distribution box supplied by Comcast/Xfinity and to the box is orange coax same as buried from pole to box by Comcast/Xfinity and a 10’ run from distribution box to the modem. I have 4 CableCARDS also. You’re suggesting a direct connect to the orange coax for a test? Is the distribution box a concern and I should maybe use just a splitter array for distribution?   Are there concerns other than Channel 33 & 34? 

Also a new ‘EVENTS LOG’ !

Try it with the direct connection. 

If everything worse fine, then go 

INcoming line------Dual splitter-------to amplifier and other devices

                                        |

                                        |

                                Modem

Have the modem on its own-unamplified line. have the tv’s on the amplified leg of it. 

Thank you. If it’s better direct connected, then just add a 2 way digital splitter before the distribution block? A 54-1675MHz MoCA 2.5 that’s -4dB on each leg would be OK?

the sb8200 doesn’t use moca. Keep it simple. Use the most basic dual splitter off the main leg to reduce signal reduction and interference. then one leg to the amp/moca and the other to the modem. 

I have a very old Genisis 5-1002MHz -110dB RFI -3.5dB legs. Is that sufficient? You mention your CM3000 modem but for my 500 or 800 Service would a CM1200 maybe be a better choice than the SB8200 if my errors continue?

The genisis should be fine. Give it a shot. You can direct connect it first and see if the modem works fine and redo your connections page (after using it for a bit)

With splitter installed as you mentioned, PC directly to modem channels 33 & 34 are still like previous images.

This is a new EVENTS LOG. What do those events signify? 

Is a solution maybe to pick up a Comcast Gateway for just testing before I have them make a house call?

Speedtest.net was 286 for a 500 provisioned plan. Speedtest.comcast.com ‘Rocket’ was similar but never 300+. I’m charged and Comcast insists I’m provisioned for 500.

*** The splitter seems to have helped my TiVo’s. They were maxing out(100+) and the -3.5 dB on the splitter took them to low 90’s. That I understand is a desired.