Methods of performing diagnostic tests on electroencephalography (EEG) recording devices comprising at least one stimulator coupled with a plurality of EEG electrode recording channels and corresponding recording channel connectors are performed by a test fixture comprising a plurality of resistors coupled with one or more of the EEG electrode recording channels and corresponding recording channel connectors. The methods include performing an impedance test for determining if each EEG recording channel of the EEG recording device has a predefined impedance, performing a channel uniqueness test for each EEG recording channel, performing a test for verifying the state of a switch of the stimulator of the EEG recording device, and performing a test for verifying connector IDs of the recording channel connectors connecting the EEG electrodes to respective EEG recording channels.