Agilent Technologies 5517B Operation And Service Manual page 101

1. Disconnect power from the HP 5517B.
2. Remove A4 Sampler Board.
3. Rest the test polarizer (HP Part Number 1000-0616), which is supplied with the HP 5517B, against the
exposed Reference Receiver exit port of the A6 Sampler Assembly. The test polarizer serves as a viewing
screen for examining the laser beam, which is normally incident on the Reference Receiver photodiode.
Apply power to the HP 5517B. Examine the laser beam cross section illuminating the test polarizer. It
should be circular and centered within a few millimeters with respect to the exit port. Slight eclipsing is
normal. If any intensity variations are visible across the beam diameter they should be straight, regularly
spaced lines of high and low intensity - not spots or irregular shapes. Rotate the polarizer 90 degrees and
repeat the above observations. The A6 Sampler Assembly can be removed and the internal beam splitters
and polarizer's examined for scratches dirt or cloudiness. Check the A3CR5 lens for scratches, dirt, or
cloudiness. Also, see Liquid Crystal Troubleshooting, step f.
If ending troubleshooting procedures at this point, disconnect power from HP 5517B Laser Head, set all test jumpers
to their left-most (normal) positions, and replace front panel and side covers.