A high-speed signal subsystem testing system tests a processor transmitter and receiver coupled to a connector via a transmitter trace and a receiver trace, respectively. A transmitter test circuit on a testing board coupled to the connector compares a transmitter voltage received from the transmitter via the transmitter trace and the connector to a common mode voltage range and, in response to the transmitter voltage being outside the common mode voltage range, provides a transmitter trace issue signal. A receiver test circuit on the testing board coupled to the connector transmits a first test voltage towards the receiver, compares a second test voltage detected at the receiver test circuit in response to transmitting the first test voltage towards the receiver to a reference test voltage and, in response to the second test voltage being above the reference test voltage, provides a receiver trace issue signal.