Hello again,

I tried hooking up my PowerBook G4 to the 520 directly with an Ethernet cable, making AppleTalk active and while I didn't have any luck with the Apple branded AAUI-15 to RJ-45 transceiver, I did at least get the status light on the Asante to light up solid green and flicker rapidly at times so maybe the port is working... That's good news at least! To be honest this troubleshooting is going over my head now so I'll try reinstalling the operating system in summer when I have some more time and look into your suggestions more in-depth at that point if a reinstall is a no-go.

Thanks for your assistance ClassicHasClass and John!