These tests will pass if the Pulse Pal components you soldered are electrically connected, but may not detect more subtle performance and reliability problems (i.e. a faulty Arduino board, DAC IC or DC converter). For a more extended validation procedure, see the Pulse Pal publication.
Plug Pulse Pal into a computer, and ensure that its drivers, firmware and software are installed.
Verify that the oLED screen displays "Pulse Pal vX.X; Click for menu".
Send new parameters to Pulse Pal via USB to verify communication (see MATLAB, Python or C++ documentation).
Connect each output channel to an oscilloscope and verify that pulse voltages and timing are correct. Check +10V and -10V pulses to verify the ends of the voltage range. Observe that the indicator lights above the output channels turn on.
Connect a second Pulse Pal output channel (or other 3.3-5V logic pulse source) to each trigger channel and verify that output channels are appropriately triggered. Observe that the indicator lights above the trigger channels turn on.
Zoom in to ~50 mV/div to verify that when set to 0, the resting voltage is within 15mV of 0V (or within 1mV for Pulse Pal 2).
Trigger neighboring channels, to make sure there is no analog cross-talk. On Pulse Pal 2 the only common signal should be a small glitch artifact, which occurs when the AD5724 is updated (1μs duration, 15mV). Pulse Pal 1 has a higher noise floor, and ~50mV p2p digital feedthrough from the SPI bus should be visible.
Program a channel parameter using the thumb joystick. If the menu screen changes when you click the joystick, the joystick button is working. Also verify its up, down, right and left functions when setting a numerical parameter (i.e. Phase1Duration), and validate the parameter change with the oscilloscope.
Next, disconnect Pulse Pal and plug it back in to ensure that the EEPROM circuit has properly stored and recovered your channel parameter. For Pulse Pal 2, which doesn't have EEPROM, save a file to the microSD card and make sure the parameters are recovered when you power-cycle and load the file.
Play a long pulse train.
More extensive performance and reliability tests are described in the Pulse Pal publication.