Jack Swigert is attempting to activate the CMC in the freezing-cold command module, which is more than essential to allow the crew of Apollo 13 to do a proper re-entry. He mentions over the loops that he's unable to get the computer to go into standby. As GUIDO Ken Russell troubleshoots the problem with Jack Garman in the backroom, Garman almost flippantly remarks that this particular computer has a history of having trouble with going into standby. Not something that anyone wants to hear at this particular phase of the mission when everything is already in a critical state.
Link:
https://apolloinrealtime.org/13/?t=138:19:41&ch=21Edit: One particularly humorous (in hindsight) remark towards the end of the conversation is "You can always come up by powering down and powering up the computer again." How many times have we heard this when dealing with tech support in the 21st century?