Back to Plusnet (from Sky) but router issue

[#1]

Great service in the move back from Sky - whose customer service is abysmal.
I have an issue though - I have two ethernet cables from the Technicolor router -  the shorter one that is connected to the TVs via 2 switches is OK.
The longer one that goes to an office upstairs no longer works , which it did when connected to my previous plusnet router (d-link from memory) and to the Sky router. I have tested it into the switch it was in as well as directly into a PC.
I have my PC and ATA (Vonets dongle)  working via WiFi [previously connected to the switch]  but one laptop that has to function via a wired connection to achieve VPN to work remains to be connected.
My question is; is this a known issue with this router?    I have yet to do the obvious and check the cable - more difficult than it seems!!!!
Thanks Allan

[#2]

You could check there's not a fault on the other ports of the router by connecting your ( working ) short cable to the other ports in turn and checking that your TV's work. If that tests OK then it looks like it's a cable problem.

[#3]

Quote from: dfstrottersfan

My question is; is this a known issue with this router?

No.
Is there any chance you set fixed IP addresses on the LAN ports of your devices that don't lie within the address range of the new Plusnet router?

[#4]

Hi, I haven't come across this before.
Graham

[#5]

It seems to be a fault in a cable that worked OK for 4 years or so , I managed to borrow a really long cable which works, though it is now a hazard negotiating our stairs:-)
Thanks for the suggestions