Ok James,
You have the tm-D710 2m/70cm aprs radio, correct? If so it uses the same radio body as tm-V71 dual band, I have some of both here.
Give me a day or so to revise the D710 setup and find the cable I used on my tm-D710 head, so I can swap it with the V71 head on the setup now. I remember making a few cables at the time, I think there are spares, I need to check which head.
If you made 10 cables they cant all be duds! The best way I know to check the two cables is,
If you can see the wires are connected to the right pins in those horrid RJ45 plugs, plug the end in the radio, and with a normal meter set in the high ohm range, you should see some continuity to the DC 0v wire of the radio on every pin that is used, also the DC 0v wire in your cable should be zero ohms, the others will be something higher.
Completely open in the megs range indicates the crimp is bad at one or both ends OR the connector is not contacting the pin in the radio when inserted.
Also check for shorts on the adjacent pins. ie 1 to 2, 2 to 3, 3 to 4, etc across the plug.
If all is good repeat the above process from the other end of the cable with it plugged in the RRC.
If you have made a few cables and one passed that test you could be confident you have radio socket pin to RRC socket pin contact.
It can happen that the RJ45 plastic divider guides is burred or some other debris holds of a contact when the plug is pushed in the socket. The cable looks great, checks out end to end but no contact on one pin when its plugged in will have you tearing your hair out.
We can also check from your head to my remote and visa versa which helps figure out which ends got the issue.
If you can PM me an email addy we can exchange configs etc.
Harry
Vk3bia, Bali.