Troubleshooting

If the LI-5700A Spectrophotometric Seawater pH Analyzer is not functioning properly, check for the following common problems.

Communication problems

  • Are the cables connected properly?
  • Check the serial adapter cable. Tighten the screws that hold it to the control unit connector. Be sure the temperature cable connectors are tight.
  • Incompatible cable or adapter?
  • Be sure to use the cables provided with your device. Other brands may provide inconsistent performance.
  • Correct COM port settings?
  • To find the serial port number, open the Device Manager (press the Windows key , type Device Manager, then press Enter). Click Ports (COM & LPT). Look for USB Serial Port (COM#). The serial port numbers are shown beside the ports.
  • Computer needs a fresh restart?
  • An occasional reboot can resolve a variety of mysterious PC issues. A fresh start every morning helps keep them from ever appearing.

Measurement issues

  • Dirty windows on the optical cell?

  • If the plot in Current Sample Results has a jagged or choppy appearance, clean the cell windows as described in Cleaning the flow cell.

  • Optical cell poorly aligned?

  • Check the optical cell alignment (see Positioning the optical flow cell).

Power supply problems

  • Suitable power supply?

  • All components require a 100 to 240 VAC power supply (50 or 60 Hz). If a component is not functioning properly, check the power supply and adapter cables.

  • Open circuit breaker or GFCI outlet?

  • Check circuit breakers and GFCI outlets to be sure they closed. If a circuit breaker or GFCI outlet is being tripped repeatedly, there is another problem.

  • Power cords connected?

  • Check the power supply cords to ensure they are connected properly.

Solution problems

  • Air bubbles in the tubes?

  • Bubbles in the blank cell will result in unstable blank readings. Check the tubing and make sure that no air bubbles are trapped inside. Use the Flush Cell utility to discharge the solution (and bubbles) from the flow cell.

  • Contaminant or particles suspended in the liquid?

  • Suspended particles should be filtered; they may block the tubing and light path.

Syringe problems

  • Home position not initialized properly?

  • The Home position is found automatically on initialization. It will not initialize properly if there is liquid in the syringe or if the outlet tube is restricted. Be sure liquid can flow freely out of the syringe when the plunger moves, and then Initialize again. If you need to remove the syringe, follow the steps in Removing the syringe.

Cary 60 spectrophotometer

The Cary 60 Spectrophotometer includes complete documentation provided by the manufacturer. Refer to the included instruction manual for troubleshooting.