took me, to identify it and two trained elctricians to rectify.
Some pratt used a 440v power cable for the warehouse neons to support the comms cable on part of the run. Every time the lights got turned on the terminal (in block mode) had a fit.

Thin client might be a better description admittledly. Not sure how it would fair when you induced a cascade of 40 massive spikes in the utp cable though.