before run 17493 we got some WFD warning (Hit fract out of tol <.04 | >.8)
from SM5 CH28, corresponding to the counter 5E08-0 which showed a very bright
PMT signal.
Yesterday, we found out that it was due to a light leak because the safety
bar was pratically unscrewed.
After having tightened it, the problem desappeared and the PMT signal is fine
now.
A presto,
Massimo