After a number of years, the on/off button gradually became less responsive. I wasn't really surprised. These silicon rubber buttons are not the most durable type of switch. They usually have a small pad of conducting (graphited) rubber that is pressed against a PCB to connect two traces. They can only handle a small voltage and current, to provide an input signal to an electronic control unit. I have had some experience in cleaning these. That sometimes works, but there are occasions where the black discs of conducting rubber seem to have lost conductivity. There are people who claim they have used conductive paint to enhance the graphite pads, but I haven't tried that yet.
Late 2013, the switch became almost unworkable. I decided to take the plunge. If the buttons could not be repaired, I could always replace them by a standard pushbutton. But first, I had to get into the machine.
Now Krups is one of those patronising manufacturers actively hampering their customers' rights to repair their own property. They have used 8 undriveable screws to keep the case of the coffee maker closed. I saw featureless cylindrical heads that don't fit any type of screwdriver. I first thought they were nails or rivets. I found this quite aggravating. Do they want to force me to buy a new one? Not this guy!
I remembered having read a blog on this subject before by Rolfje, How to fix a Krups XN2001 Nespresso machine. This home repair hero had found out the nature of these screws. The first two of these screws become accessible after the dripping tray is removed. Using my Dremel tool with a thin grinding disc, I could make a slit in the heads and unscrew them.
Two screws in the bottom I could remove just pinching them with a pair of thin needle nose pliers.
It turned out that these last four screws hold the side panels, two for each side panel. These side panels I needed to remove to get access to the switches. It turned out that the first four screws I had removed hold the bottom so I could as well have left them in place.
Inspecting the on/off button, I saw that the PCB was slightly dirty and had some water traces on it. I cleaned it using a cotton tip with some contact cleaner and toothpaste, then alcohol to remove any debris. I cleaned the rubber contact pad using alcohol only. Left the components to dry and put them together. To my surprise, this worked right away. The machine went on and off easily. I cleaned the other button, too, now I was at it.
I inspected the rest of the machine. All components were looking fine. One finding: according to a label on the water pump, it may only be switched on for 1 minute, must then rest for 1.5 minutes (at 230V) or 2 minutes (at 240V). I don't remember this was in the machine's manual.
In order to be able to replace the screws, I placed them in a row and using my Dremel and thin grinding disc I cut a slit in their heads. After that, I could replace them using a regular flat-head screwdriver.
My father would have been be proud of me. I was able to overcome the selfish, childish, patronising, hostile, debilitating, irritating obstacles that Krups put in my way to prevent me from fixing a technical object in my possession. I was able to prevent wasting money on replacing an object that could easily be repaired and I have learned something in the process.
After making this report, I found there is a whole blog on repairing various faults on these Krups machines: Great work! There I learned that the heads on these screws are actually not cylindrical but but oval and that screwdrivers for them do exist.
To remove the side covers of this machine, you first have to remove the bottom console. The side panels have locking tags that prevent them from being removed. After the bottom is removed, they can. After that, it is possible to take off the top cover and the panel holding the two rubber push buttons.
We were not able to find a clear cause of the leakage. Most of it lands in the dripping tray, which is ok. The cause is probably some slack in the closing mechanism, caused by using “compatible” capsules with a hard rim. The rim of the capsules must form a seal, but the “compatible” capsules use different material that is slightly harder, which may damage the mechanism. As a result, the seal is not pressure tight with all capsules any more.