YO

I am facing a problem with shimadzu autosampler. It says," unable to home 6 port valve". The instructions manual suggests to reset the instrument and if problem persists call shimadzu".
Do you guys have any solution to this problem?

Reply asap, its urgent


thanks

What model is this? Is this valve mechanically actuated or pneumatic (air pressure)?

In general, this kind of error suggests that the valve is not switching back to it's "home" position because either it is frozen or the actuator is not working.

Do you hear any sound at all from the valve?

Since its making a sound it would seem that its attempting to actuate.

Assuming this is a pneumatic valve; verify the tank pressure that drives the valve. If you are using a mechanical compressor, ensure that there is no moisture coming through the line (this is very common when the temperature is up).

Standard 6 port valves are "messy" to replace, but if you simply take care where the lines attach, they are not a major problem to replace on your own. The main point in attempting to replace something like it is;

1) Turn it off (if not for your own safety, then I've blown circuit boards by dropping a bolt in the wrong place).
2) Label everything as you disconnect.
3) Take some pics (my kids use there cell phone to take pics of the friends - I use mine to take pics of whatever I'm taking apart).
3) Pay close attention to the orientation of the valve (the pics should help).
4) If this is a standard Valco valve they are often available directly from Valco.
5) Reassemble.
6) Be careful when tightening. There is a bit of an art not to have the system leaking while not over-tightening.

Hope this helps.

Greg Pronger

I am almost certain that this autosampler uses electronic actuation, but I was unable to confirm with my initial investigation. You either have a frozen valve or your actuator is defective.

As suggested, very carefully disassemble the valve and look for signs of corrosion, leaking, etc.

Is this an old system? Have you been using buffers in your system? Are you careful about flushing them out?

Write back to tell us what you find.

yo

I have dissembled the autoinjector and couldnot find any leaks, rusts or any other abnormalities.
After cleaning all the parts of the valve and reassembling it the problem still persists.
I was using buffer solutions but was flushing it regularly and autoinjector was on automatic rinse after every injection.

The good news is that you have been taking care of your instrument, and not abusing it like many buffer users do. The bad news is that you probably have a bad actuator, since it is making noise but not moving. Time for a service call, or at least a call to the support line.

Sorry we couldn't come up with anything better. Let us know how it turns out.