Oh, oh. I just had a caffeo solo with exact this issue. I tried to replace the microswitch of the power button, without success. So it might be an issue on the motherboard and I didn't look further. My first advice is to open the device and pull off the cables leading from the front plate to the motherboard and connect them again - perhaps the contact ist bad. My second advice is to replace the microswitch, a standard [link|https://www.juraprofi.de/Melitta-Ersatzteile/Ventile-und-Schalter/Melitta-Mikroschalter-fuer-den-Ein-Aus-Schalter::11858.html|Cherry D44Y|new_window=true]. For that you have to remove the front plate. (It is secured by four screws in the Corners and one screw beyond the coffee spout, which also has to bei [guide|125263|removed]). If this all does not help (and you live in Europe) think of shipping the caffeo to Melitta Germany, they do all repairs at a [link|https://www.melitta.de/reparaturpauschale-iii-fuer-caffeo-bistro-bar-lounge-ci-gourmet-passione-varianza-kaffeevol.html|fix price of about 150€|new_window=true]. (Your caffeo will be nearly new)I wish you success!