I have a noisy DSL line that feeds into a Zyxel C300Z modem.  I have a CAT5 ethernet cable (about 10ft long) going from the modem to the first TP-Link AV2000 powerline adapter in the same room as the modem.  I have a second, matching AV2000 adapter plugged into the wall in another room that is about 35 feet away.  This configuration used to work until the phone/DSL line degraded with lots of static and noise.  Now, the ethernet signal from the first AV200 adapter only works when plugged direct into my computer, bypassing powerline wiring and also bypassing my laptop's docking station that used to have an ethernet connection coming from the first AV2000 adapter. This tells me that Ethernet is getting out of the modem, but it drops out when traveling on a powerline or going thru a laptop docking station.  I am guessing this is due to signal attenuation. 

I am looking for suggestions on filters and/or signal boosters that I can put between the modem and the TP-Link wall adapter to both clean and boost the noisy Ethernet signal.  I have done all the usual things - reset and rebooted the modem, reset and attempted to re-connected the TP-Link adapters, changed ethernet connection cables, turned off big appliances or AC that might be causing interference, verified that all connections are making good contact, I am not using any powerstrips or surge suppresor connectors, and I even changed the TP-Link powerline adapters to brand new units.  The phone company repair person was out yesterday to fix the line, and today, it is still noisy.  I am out of ideas.  Any recommendations for ethernet boosters or filters or any other suggestions will be most welcomed.