Prototyping during pre-production

For the construction of the future ATLAS strip tracker end-caps, six geometries of silicon strip detector modules were designed. Each module comprises one or two silicon strip sensors and several flexes holding the required readout electronics, designed to match the geometry of each module. Due to the large number of designs, two module geometries using two sensors per ring module were prototyped for the first time in 2022, and showed excessively high noise. This contribution presents an overview of the follow-up investigation to diagnose the issue, the subsequent powerboard re-design and results from the first prototypes in 2023.