Try temporarily putting the DSL modem/router at the NID with the phones disconnected. You also won;t need a filter. This would be a quick test. One of your filters could be bad. So, you just have to plug the DSL modem into the test jack.
A reminder that you can remove the filters and use DSL as long as you don't use the phone. You can turn off the modem to use the phone.
The DSL modem does not care about polarity. I manged to find some CAT4/5 RJ11 mounded cables that did not have the twist to connect the modem. A standard telco cable would have the twist, but usually that's CAT3 (thin the grey cables).
Maintain the twists on anything that sees the DSL signal. Twists reduce EMI. Shielding reduces RFI.
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I'd ask you telco provider if they would install a DSL filter at the NID for you. Mine provided a small length of outdoor rated wire to get to my demark point. At the very least, you could have a CAT6 splice box just inside. I brought the pairs to a Leviton punch down, but the telco still gets distributed form the carbon surge protector. That point feeds about 4 lines and a run to a second block with 3 or 4 more feeds.
Just make sure you get some outdoor rated cable from them to get inside the house. Make them possibly replace the cable coming in with CAT5.
You have to terminate. That's why I terminated to a 8-way leviton punch down. RJ31x alarm jacks (allows line seizure) would add a complication.
It's hard to troubleshoot. I managed to find appropriate push on terminal blocks that will fit a CAT6 splice box. Now, I can transition 4 pair quad to the punch down block and can disconnect each leg. I'm not quite there yet. One block is in place for proof of concept.
In the second junction block, I will ultimately transition to a patch panel for both telco and Ethernet For now, running wires is tough between blocks. Initially, all patches will be RJ45's and inserts will convert an RJ45 jack to a single line telco jack for new stuff.
I only have 3 wired locations far from my "network" stuff. That was done with free terminated cable. The network stuff is on a UPS and the DSL modem is powered by an EXTERNAL POE generated from the UPS.
This
https://www.westsidewholesale.com/leviton-47609-tsv.html is similar to mine but it has the RJ31x security jack. Hindsight is 20/20.
They may have implemented it differently.
So, I have a fair number of CATx to QUAD transitioning to do and I could not find a commercial product to do it. Easy disconnection is a necessity, although I do need a test connector to have access to the pulled line or remove the spring clip locked wires.
The new blocks that Verizon insalled were super. It's so easy to troubleshoot and the quality is better.
Although it wasn;t this one, but you can see how potentially easy it is to trobleshoot.
Usually, there is a 1/2 ringer left in the NID and with the two blocks that I have it's so easy to:
1. just look at the naked line into the premise
2. Look at the line just with the 1/2 ringer
3. Disconnect the inside
4. disconnect the filter
5. Use the test jack.
Yep, it does require the "special" nose like aligator telco clips typically found on a but set.
OK, what's 1/2 ringer? It present a load of 1/2 REN to the ringing circuit so external tests can be preformed with the inside line disconnected.