The KM3NeT Collaboration is building and operating two deep-sea neutrino telescopes at the bottom of the Mediterranean Sea. The telescopes consist of lattices of light detectors housed in
pressure-resistant glass spheres, the so-called digital optical modules, which house 31 3-inches of diameter photomultipliers, as well as the acquisition electronics. The so-called detection units are vertical strings along which digital optical modules are installed. For the first phase of the construction of the telescopes, several tens of detection units have been produced, out of which almost 40 have already been deployed with more than 20,000 photomultipliers installed and taking data. Once finished, the two telescopes will have installed more than ten thousand acquisition nodes, completing one of the more complex networks in the world in terms of operation and synchronisation. This work presents the current status of the acquisition electronics, including the upgrade of the principal components such as the central logic board, the signal collecting board, switching core board and Glenair back plane.