A modular test instrument for performing tests and measurements in a network is disclosed. The modular test instrument may include a modular processing unit comprising a processor and memory, the modular processing unit connectable to at least one modular test unit or modular test subunit. The modular test instrument may also include a modular display unit connectable to the modular processing unit or the modular test unit. Display modularity may enable quick and cost-efficient display replacement when damage, malfunction, or failure is incurred. Furthermore, the modular test instrument may include an additional modular test subunit connectable to at least one of the modular processing unit or the modular test unit. When the modular processing unit is fitted with the modular display unit, the modular least, or modular test subunit, for example, the modular test instrument may form an integrated test instrument for performing any number of tests and measurements associated with installation, troubleshooting, or maintenance of a long-term evolution (LTE) or 5G network.