Phil Mitchel
They may have pulled-out one a Link 2000 and having it sitting on the shelf. Or they may have a suggestion.

Marine Electronic Sales
Bert Jabin's Yacht Yard
7310 Edgewood Road Bldg #8
PO Box 5043
Annapolis, MD 21403
Sales@ElectronicMarine.com
(410) 268-8101

Bob Campbell
Marine Electric Systems
337 South Drive,
Severna Park, MD 21146
info@MarineElectricSystems.net
(410) 647-5001

By the way, you are right about the telephone-like connector (more like a data cable). It's possible that it's something stupid like a bad connection. DON'T spray CRC into the inverter or the Link 2000 -- but you could try something to clean the contacts on the cable themselves?

Does the Link show any error codes? Does the Link show that it's actuating the inverter, but it's not? Does the link otherwise look like it's working completely (voltage, percentage charge, etc.)

I trust you've tried to per up and down. DO NOT DISCONNECT THE BATTERIES FROM THE INVERTER/CHARGER AND try to invert, you'll blow-out the boards on the charger. (You need a battery connected.)