If you've replaced your "known bad" device and the connection you had before doesn't work.... then more than that device is bad or misconfigured.
Certainly it's possible the PanelView is damaged, or the 1761-NET-AIC or one or more of your cables.
But it's worth taking a look at the difference between a MicroLogix 1000 and a MicroLogix 1200 in this application.
The MicroLogix 1000 would "auto detect" DH485 traffic and switch into DH485 mode even if its serial was configured for DF1 Full Duplex.
On the MicroLogix 1200, you have to explicitly configure Channel 0 for DH485, and can still use DF1 for upload/download by pressing the DCOMM button.