Instrument Problems

• no signal.Check if mirror covers, dark slide, dome, guider mirror or guide probe is in the way. If stars visible on TV, check ?filter for proper filter, slit, entrance mirror and grating position. Check status s for proper temperatures, voltages. Check that red LED in analog electronics box is lit. If the detector has been accidently deactivated, program will not sense this. Observe will work, but will return pixel values near zero in image. To restart the array type deactivate followed by setup irs. If the captured values are all 0000000 or 0000FFFF the sequencer has probably crashed. You should type exit in the instrument control window and then turn off the insturment power. Next you should follow the ``Restart after Instrument Power Interruption'' procedure.

• apparent vignetting. The motors were not properly initialized. Note the Durant counter setting and compare them to what was expected given the current ?filter positions. If they differ use initmtrs to reset the motor control and reposition all motors.

• system hangs during startwf. If it hangs at ``Bootstraping node 100'' it is probably because the there is not a proper link to the DSP box from the SUN. Check the connection to the BO11 board in the Sun also check that the proper Kernel has been executed during the bootup of the SUN. Power down the DSP and reboot the sun as described on page 21 under ``Restart after Heurikon DSP box power interuption''. You should watch for two messages during the bootup that tell you the B011 processes have been started. If the system hangs at ``Bootstrapping node 2'' or 10 it is probably a fiber communication problem. Check that the fibers are properly connected and clean. Once the fibers have been checked it is best to do a full restart powering down the DSP and rebooting the sun.

• System hangs on TCP commands. Verify, that serial port A on the Sun computer is connected via an RS-232 cable to the TSC computer.

• Bad images. If stange looking images which are very near zero occur it is possible that the array has become deactivated. First just try to actiavte the array and take an image. If this does not work exit wildfire, power down the DCU and analog box and restart the system. If the image of a star appears very poor with a depression in the middle, it is possible that you are saturating the center of the star. Try a shorter exposure time or move to fainter star.

• XIMTOOL Collisions. If two tasks try to communicate with an IRAF image display device at exactly the same instant they will collide and potentially kill the ximtool and hang the processes. This is not a major catastrophy and should not require a system restart, but be careful to display images or use imexamine only when the data system is not about to display an image. Alternatively, turn off the auto display type display none in the command window. If they do crash, first stop any more images from being displayed (i.e. stop the focus movie). You will then have to make sure the ximtool is dead by typing ps -aux $\mid$ grep ximtool. If it still lives kill it kill -9 nnnn. Now restart a new ximtool or saoimage. This collision may also leave imexamine in a highly confused state. You can try to heal it by typing the usual flpr commands in the iraf window. If this does not work kill the iraf window and start a new one.