Even though there is enough water, when the middle light stops flashing the right light (2 cup) does not come on. If I shake the machine a little it finally comes on and I can get a double shot. Is it the reed switch inside the reservoir? It looks like both switches are moving up and down fine. Thanks

SOURCE: espresso machine

Sometimes the rubber seals on these can be very "stuck" after not being opened for a while - about the best way to free them is to pour a little hot (near boiling) water around the outside of the lid to soften up the seal, make sure you are trying to turn it the right way (anti-clockwise) and give it a little force. You can help prevent this in future by lightly greasing the seal with a tiny bit of vegetable oil - sunflower oil works fine but most should do the job. if the rubber seal looks very distorted or cracked then take it to a hardware store and see if they can find something the right size or try philips support from the same link below. get the user manual here (sorry not available in english, but is available in most other main languages) http://www.p4c.philips.com/cgi-bin/dcbint/cpindex.pl?slg=AEN&cat=KAP_COFFEEMAKERSANDKETTLES_CA&sct=CK_ESPRESSOMACHINES_SU&session=20070307124515_83.54.34.75&grp=KITCHEN_APPLIANCES_GR&ctn=HD5661/90&mid=Link_UserManuals&hlt=Link_UserManuals Hope this helps :)

SOURCE: Senseo coffee maker

Having dismantled and inspected several of this "strange machines" my conclusion is the following:

There is an oscillating-piston pump inside with in- and outlet valve.
It is energized by a microprocessor controlled circuit for a working time depending on the button selected (1 or 2 cups). The pressure and flow are nearly constant for a perfect working pump.
The pod holder restricts the thruput by its central hole. (E.g. you get now an extra pod-holder with a very small hole for expresso type)

So if you don't get enough coffee it may be that
1) the duty-cycle (timing) of the pump has changed.(not often occurring) no repair, you have to undergo electronic and programming work
2) the pump lost efficiency (cylinder of the pump clogged, piston not working with complete stroke, spring force fadening or just one of the 2 valves leaking) ca be "repaired" after dismantling machine ,extracting pump and taking it apart, success not garanteed - grinding valves is already time spending
so my principle before starting this work is to run the machine without the coffee pod to check the water output, use a new holder with clean central hole, if this works it will be nr.
3) the central hole of the holder is clogged, may be not by limestone, but dried coffee extract (grease) clean with needle or even better with micro-drill

SOURCE: one coffee cup button switch not wotking properly after 6 months

Call senseo at 866-4-736-736 866-4-Senseo and describe the problem.
if you have purchased or received it as a gift less than two years ago they will send a new one FREE.