There is no internal fuse for the 12 volts on the tuner connector. There is a surface mounted choke on the DDS unit that’s probably
burned out. Depending on how bad it is, there might be some circuit trace damage too.
I just purchased this Icom 7000 used and connected it to my Icom AT180 tuner. It was connected to my 7300 and worked fine. No tune on 7000 so I checked for 12 volts on the tuner plug but its zero volts. Is there an internal fuse that
may be blown? Does any of the Menu settings turn off the 12 volts? Did I buy a dud?