go flatline
[from cyberpunk SF, refers to flattening of EEG
traces upon brain-death] vi., also adjectival `flatlined'. 1. To
die, terminate, or fail, esp. irreversibly. In hacker
parlance, this is used of machines only, human death being
considered somewhat too serious a matter to employ jargon-jokes
about. 2. To go completely quiescent; said of machines undergoing
controlled shutdown. "You can suffer file damage if you shut down
UNIX but power off before the system has gone flatline." 3. Of a
video tube, to fail by losing vertical scan, so all one sees is a
bright horizontal line bisecting the screen.