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Thermo Fisher Scientific

No Light Displayed on Valve


The LED indicator which indicates whether the valve is in either the Load or Inject position is not illuminated (see red box in image below)



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1. The valve should be snug up against the black mounting collar (yellow circle in Figure 1). Also, the valve should not physically move when the motor toggles between Load/Inject. If you see movement, you will need to tighten the screw. If you need to make an adjustment, you can use an Allen wrench on the screw circled in green in Figure 1.

Figure 1

2. If the valve has been replaced:

a. Verify that there is a coupling (see Figure 2) that needs to be set to interface between the motor and the valve. Verify that this is in place.

Figure 2

b. Power-cycle the autosampler (or syringe module) to recalibrate/re-index the valve. Turn the autosampler off for a few seconds and then power it back on. You will hear  clicking and then the Load/Inject lights will flash for a few seconds. When completed, the Load lights should be illuminated on the valves. 

3. If trouble with the valve is still being experienced, remove the valve from the valve module and then power cycle the autosampler (or syringe module). Observe the motor. The pin should move back and forth similar to this movie while powering up.

 If it is not moving properly, the actuator is not  working properly and the valve module will need to be replaced.

4. Inspect the valve pin to make sure it hasn’t come out of alignment. If it is rubbing up against the side (image below) then it may not toggle properly and produce this issue. If it is out of alignment, the valve will need to be replaced


There should always be either a Load or Inject light illuminated on the valve. The light will not be displayed when the valve controller can detect that it's not switching properly



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