We repaired a Siemens MicroTech4 MT3106 Base Controller (POL688.80 MCQ) that was experiencing malfunction in control and communication functions. Our team carried out detailed diagnostics, identified defective circuit components and driver sections, and replaced them with high-quality parts. After repair, the controller was tested under simulated load conditions and performed reliably without errors. This ensures stable and efficient operation in building automation systems. Please note, we are not manufacturers — we provide repair services only.