Disconnecting in-wall ethernet connection

[Conquerred512]

Hey everyone. Been awhile since I've posted here, but I'm finally at my wits end with this issue.

Quick explanation of the setup:
External Fios box passing in ethernet to lower floor
-> Netgear R6700
-> ethernet passes along ceiling to living room above
-> panel in LR -> ethernet to my desktop

Occasionally, my connection to the living room drops completely thinking there's nothing plugged in ("No Connection"). Been happening for a number of months. When it happens and how long it lasts is non-deterministic. Sometimes, messing with the panel seems to help, but that may be pure coincidence. Last night, the connection went out and no amount of messing seemed to help (I then went to bed in frustration).
For other debugging info:

Router maintains a connection (wireless keeps running)
Connecting a separate ethernet & computer to the panel stays disconnected
Swapped ports on the router -> nothing
Connected laptop & ethernet directly to R6700 and its fine

I originally was using a switch in the basement and had the Netgear in the living room for better wifi, but this issue popping up made it painful since wifi would then drop. There are other in-wall cat lines, but I haven't tried them since I haven't scoured to see where they come out.

I think I'm at the point where I should just rip out the line to the living room and install a new CAT 6 line, but the intermittent behavior (I swear there was a time when it happened only on Friday nights....or I'm going crazy) of this issue has me absolutely stumped. I figured a bad cable would just be dead, not random levels of dropping out.

Is there anything else obvious I should be checking here or other recommendations besides just ripping it out?

 

[eibgrad]

This is the line that got my attention.

Connected laptop & ethernet directly to R6700 and its fine

That suggests the problem lies between the R6700 and the desktop and all that rather vague description about running ethernet along the ceiling and "panel" (?).

Is it not possible to similarly run ethernet directly between the desktop and the R6700?

If not, and wireless is not an option, consider powerline adapters. Doesn't always work, but when it does, it's often more stable, and usually more than adequate for most applications.

 

[Conquerred512]

That suggests the problem lies between the R6700 and the desktop and all that rather vague description about running ethernet along the ceiling and "panel" (?).

Apologies for the vagueness. It's just an ethernet running along the basement ceiling and then quickly runs through a wall (unfinished area of the basement) and up into a wall panel on the floor above (shared by a couple coax's).

I'm also fairly convinced this line is to blame. Its just the intermittent behavior that has me stumped in confirming. Wouldn't a bad cable just be bad? Not "sometimes maybe, depends on the day and weather and how it feels" bad?

Desktop is on a separate floor, hence the in wall line, panel, and additional cable. With the laptop I was just standing next to the work area in the basement where the 6700 is and hooked it up.

 

[bill001g]

The cable itself is seldom bad unless it some how was damaged. Mice love some plastic ethernet cables. In the vast majority of the cases the ends are got loose or damaged. You get all kinds of strange issues when a connection is marginal. Temperature changes that have no effect on a good cable can cause a bad one to intermittently fail.

It tends to not be cost effective for a end user to buy the equipment that will really test cables...those cheap cable tester only test very simple failures.

Your pretty much blindly cut the ends off and reterminate them. Although a little more expensive keystone jacks tend to be easier for inexperience people to get cable terminated correctly. You can do 1 wire at a time rather than hope to get all 8 lined up and not slip as you crimp on rj45 ends.

 

[eibgrad]

Wouldn't a bad cable just be bad? Not "sometimes maybe, depends on the day and weather and how it feels" bad?

When a cable goes bad, having it work intermittently is quite common. Depends on the type of damage. If there's a minuscule break in one of the internal lines, even the slightest vibration, change in temp, etc., could lead to intermittent connectivity. It's actual quite rare for a cable to break cleanly and refuse to work at all.