Philips AC4118 - Manual (Page 13)

Problem Solution
The corona particle
charger is still dirty after
I have cleaned it with
the soft cleaning brush.
This is not a problem. By brushing the top and bottom of the corona
particle charger, you remove enough dirt to make it work properly
again.Never touch the corona particle charger with your hands. Always
clean the corona particle charger with the special soft cleaning brush,
which is stored in the front panel. Be extra careful when you clean the
corona particle charger: the wires are very fragile.
The appliance produces
sparks during operation.
Sometimes small sparks may be produced in the corona particle
charger. This is quite normal and the result of moisture in the air.
English 1