How about trying to find the PC with the beaconing condition? That shuts down the entire ring? Usually someone copied another DOS PC configuration that uses the same Token Ring address. Engineers were good for that. 1994 or 1995 and they bought a new PC and instead of filling out sheets to have IT set up the PC they tried to do it themselves.

Ha! Even Ethernet used to be a lot fiddlier in the '90s, when you had to worry about crossover vs patch cables.