when you're facing the front of the machine, it's the left cover that
you need to remove to see the solenoid. there's 2 screws holding the
cover, one at the front behind the front door and one at the back behind
the rear door. then remove the paper cassette and ply the cover off
both at the front and rear, downward to remove.
once the cover is
off, look at the front end and you should see a larger black gear with a
spring attached to it at a 45 deg angle. right behind the spring is the
solenoid of interest. if you do a print, the solenoid should be
triggered once and the black gear should only rotate once. if it rotate
more than once, the solenoid arm is sticking to the sponge pad. use a
small blade or flat head screwdriver to remove the pad from the solenoid
and hopefully your problem should be solve.