Service manual

Troubleshooting
Revised 2/18/05 6-25
3. Connect the + and - outputs of the electrical
stimulator to the input of the load/attenuator test
fixture. Connect the attenuator outputs to the + and
- inputs of your system’s headbox or amplifier
module. A connection to Common is not
necessary.
4. Set the control panel’s Stimulus Intensity knob to
maximum, and begin stimulation. If everything is
set up correctly, the electrical stimulus pulse
should appear on the display. The example below
shows the electrical stimulus pulse on a
VikingSelect, using the SEP test mode.
5. Turn the Stimulus Intensity knob up and down, and
watch for a smooth amplitude transition.
6. Set the stimulus intensity back to maximum, and
collect an average of ten sweeps.
7. Using the cursors, measure the voltage levels at the
leading and trailing edges (peak and droop points)
on the waveform. The peak should be 400V
(400V/100,000 = 4mV measured on the screen).
The leading edge tolerance is +20V/-40V. The
trailing edge should measure 360V (3.6mV), with
a tolerance of
+40V/-120V.
8. Change the stimulus duration to 0.1ms. With the
Stimulus Intensity knob set to maximum, the
stimulus pulse should reach its maximum value of
400V. The rise/fall times of the pulse should be less
than 100us.
9. Change the stimulus type to Current with a range of
100mA, and repeat steps 3 - 8.
10. If your system has S403 Stimulus Probes, change
the stimulus mode to Remote, and repeat steps 3 -
9.
11. If your system has two stimulator channels, repeat
steps 3 - 10 for Channel 2.
VikingSelect SEP Test Set Up for Measuring Electrical Stimulator Output