I have a problem with newly installed CAT6 ethernet cable outlets installed in a new summerhouse - the cable then runs down conduits and up to the house loft (about 100ft run of cable) where there is a standard power point - then connected into a pair of 9 year old Devolo Powerline adaptors and down into the Sky router. Both Devolo have all the green lights on. The problem is that at the Summerhouse end there is NO ethernet found on my PC (done diagnostics). On test the PC finds the router from the loft via the Devolo Powerline adapters. The long Ethernet run is wired correctly and was tested (8 green lights flshed in rotation to prove it's wired correctly). So my question is this:- Is the 9 year old Devolo simply out of date and not up the the job and causing the problem and therefore I need to replace with new TP-Link Powerline adaptors OR alternatively is the ethernet run simply too long??? - any ideas anyone?