This is the Service Manual for the TV110 CableScout Metallic Time-Domain Reflectometer (MTDR). This manual gives information for servicing the instrument to module level. The Introduction provides strategy for servicing and details Tektronix service offerings. If you are not familiar with the operation of the TV110, read the Operating Information section to become familiar with the controls prior to attempting any servicing. Use the Theory of Operation section to learn how the TV110 electronics function. This might give you a better idea of where to look for problems. The Performance Verification and Maintenance sections provide the necessary information you need for putting the instrument back into useful service. The Replaceable Parts section provides you with part numbers for ordering electrical modules and mechanical parts.