During the observation of PSR J0537-6910 on 21-may-2002 (PD 3062),
PCU 4 (out of 5) broke down at 264630900 MET, but did not turn off
until about 430 seconds later. Will has looked at the data and
determined that PCU 4 only violated the criterion for 2 intervals
instead of the required 3 intervals at 264630900 MET.
It is not clear to me why the detector turned of at 264,631,330.

This tripoff was noted in the Shift Report (20020522_A.SRG):

Spacecraft anomalies:
PCU 4 experienced a trip off during the 141/20:23 - 20:50 goodtime.  It was
not recorded in the delog so a best guess as to trip off time was established
and plugged into the Std 2 rate calculator.  PCU 4 resumed normal operation
at 142-06:21.

report prepared by Frank Marshall