* Check that you've got the light path right: guide mirror centred and the rear-of-slit mirror in the beam
* Then check that it's not an image scaling issue, by turning on the slit illumination (which is bright enough to show up under most circumstances)
* If you still don't see anything, go behind to the desk in back of the control room and find SpUpNIC PC (top right corner of the shelf above the monitors)* Unplug the USB cable labelled marked "spupnic lodestar camera" going into a USB/fibre extender box at the bottom of the electronics rackand plug it back in again* gently unplug Start the exposures again and re-insert use the grey USB cable into slit illumination to check that the ICRON box camera is alive* alternativelyAlternatively, one can unplug and re-insert the black USB cable that goes into the actual camera (which projects through the south cover of the instrument)* start instead of on the exposures again and use the slit illumination to check that the camera is alivePC end
==Technical Notes==