Some coffee machines have an Aroma Control knob. This knob allows you to adjust the strength of the coffee to your own taste. If you want to use the Aroma Control knob to determine the right balance between ground coffee and water, do not use a permanent filter. Because of its weight, a permanent filter disrupts the coffee-water balance of the Aroma Control system.
If the above solutions did not help to solve your problem, please contact the Philips Consumer Care Centre in your country.