For reference, this is the correct pinout for URC serial remotes:
[Link: remotecentral.com]And this is the WRONG pinout:
[Link: remotecentral.com]And yes, the cables definitely do wear out - the conductors eventually break from flexing. You can try pressing on cable where it goes into the jack, like holding it up/down/left/right as you try to connect. Sometimes you can get it to work, or at least get something that would prove the cable's bad.