Tchibo Cafissimo Mini Red Light Flashing, Buttons Not Responding

I'm having an issue with my Tchibo Cafissimo Mini coffee machine. It's constantly flashing a red light, despite the fact that the water tank is completely filled. I've cleaned and refilled the water tank several times, yet the problem continues to persist. The buttons do not illuminate and pressing them has no effect. Any assistance in resolving this issue would be greatly appreciated. Thank you in advance.