Diffusion pump

Cooling fan for the high vacuum pump is not working

Air intakes to the cooling fan are blocked

Blocked air intakes can prevent the fan from efficiently cooling the diffusion pump.

  1. Remove the upper and lower MSD covers.

    WARNING! Do not remove any other covers. Dangerous voltages will be present.

  1. Check the air intake slots on the front of the lower MSD cover. Make sure they are not blocked.

  2. Check the safety grill over the fan. Make sure it is not blocked.

    WARNING! Do not remove the fan safety grill while the MSD is on.

See the MSD maintenance documentation for instructions for removing the MSD covers.

Laboratory temperature is too high (generally above 35°C)

Check the temperature in your laboratory. If the temperature is too high, the fan may not be able to cool the diffusion pump.

Diffusion pump fluid level is low

If its fluid level is low, the diffusion pump will not work effectively. Check the level of the fluid in the diffusion pump. If necessary, replace the diffusion pump fluid.

See the MSD maintenance documentation for instructions for checking and replacing diffusion pump fluid.

High vacuum signal cable is not connected correctly (diffusion pump)

Check the back of the MSD. Make sure the high vacuum signal cable (HI-VAC SIGNAL) is securely connected to the back panel of the MSD.

WARNING! The diffusion pump operates at dangerously high temperatures. Do not try to check the high vacuum signal cable connections to the diffusion pump unless the MSD is off and the diffusion pump has had enough time to cool.

Diffusion pump temperature sensor is not working correctly

Contact your Agilent Technologies service representative.

MSD electronics are not working correctly

Contact your Agilent Technologies service representative.