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4.3.3 Laser Setup Troubleshooting
The appearance of the peak does not necessarily correlate with sample focus. It is normal if
the sample is out of focus whilst the peak is present.
If the signal is a flat line with no features and no features appear following refocusing, increase
the laser power in 500 unit steps and see if any features appear.
If the signal is very noisy and no peak is visible, decrease the laser power in 500 unit steps and
see if any features are retained.
If the peak is short, increase the laser power in 100 unit steps until it reaches the optimal height.
If the peak goes over the top of the y-axis of the graph, reduce the laser power in 100 unit steps
until it reaches the optimal height.
If there are multiple features on the graph, which have intensities above the baseline noise,
this can affect the Auto Set Centre function. If the calculated centre of the sensor does not
correlate with the peak, go to the pinhole submenu and reduce the pinhole width in order to
exclude these features. Please refer to the section 7.2.1 for further guidance on this topic.
(Line Mode only) If you are having trouble with the 45
o
adjustment step with your highest
magnification objective, switch to the next highest magnification objective. Note the extra care
will be required when configuring the highest magnification objective with your sample later in
the procedure.
4.4 Creating signal imbalance
Ensure the controller is in MAN FOC mode.
Ensure the setup submenu graph is open.
Rotate the digipot in such a way that the single peak splits into a broad signal with peaks on either
side. The direction of rotation is system dependent. If the signal does not split, and just becomes
broader and less intense, rotate the digipot in the opposite direction. Increase the laser power such
that the split peak fills as much of the vertical axis as possible
