Opening the strobe and the sensor:
To open the strobe or the sensor, it is necessary to remove the
O-ring from around the front window. The lens then pops out,
or can be pulled out using a rubber sucker. Removing the O-ring
is quite tricky without damaging it. It is possible to run a
soft plastic tool along the O-ring to make it bunch-up until
a loop pops out. It is the same arrangement as that which keeps
the front glass in the W-Nikkor 35mm f/2.5. The destructive way
is to slide a scriber (sharp point) into the rubber and haul
the O-ring out, but then the O-ring cannot be re-used. Also,
it is essential to avoid scratching the O-ring groove.
