reply to dalepa
Re: [DVR] Can someone explain this? Yes, rodents like to chew on cable to keep their teeth sharp. Squirrel chew on outside cable is pretty common.
Your signal will double when you go from a 4 way to a 2 way splitter. Generally -10dBmV is the minimum amount of signal needed for a digital signal. You are right on that threshold so I'm not surprised that your picture would go in and out depending on which splitter you are using.
If you have damaged cable you are possibly letting in ingress as well. Not only could this affect your picture quality, but it can also add upstream interference on the cable plant. This could not only affect your modem performance, but can affect others in your node as well. If it's bad enough, your service could be interrupted until it is corrected.