System-level testing of electronics is an affordable method of assessment of the performance of complete electronic systems designed for applications in the radiation environment. Compared to component-level testing, system-level test offers a much smaller degree of observability about the performance of particular system elements. The information received during the irradiation of a system might be therefore not sufficient for the identification of every system under test (SUT) malfunction. As a consequence, no action might be taken to recover the system operation while certain parts of its functionality would be lost due to the radiation-induced effects. This can lead to the incorrect execution of the system-level test and improper conclusions about radiation-induced effects. The present paper demonstrates a method allowing an efficient identification of system-level failures based on the system total current consumption monitoring. The proposed technique can be easily implemented with common instrumentation and at the same time provides valuable feedback on SUT operation. The retrieved current consumption information can be used to identify system failures that may be not observable through the communication channels that are by default included in the tested setup. Furthermore, the posttest analysis can be performed on the collected data to investigate the SUT condition along the complete timeline of its irradiation. The verification of the proposed method was performed during the qualification test of a system designed for applications at the high-energy particle accelerator facility.