Case Studies All Enhancing SUH Box Reliability on the Class 390 Fleet Obsolescence-Resilient Repair of Electrostar Fleet DCUs Jubilee Line trains nine-year overhaul project Resolving Thermal Incidents in Door Control Units (DCUs) Minuetto Train Door Control Units – Alstom Italy Siemens Class 333 Cab Display Unit (CDU) Overhaul of 4000 Class 390 Power Supply Units Televic – Brexit Challenge Class 175 Door Control Unit Overhaul