Troubleshooting the STA Compact Service Part 2

Tutorial on determining the source of an issue for the STA Compact, Part 2: Endurance problems. See also: parts 1, 3, 4, and 5.

A Transcription of Troubleshooting the STA Compact – Service Part 2

What I have done so far is, I have checked out the wash wells, the vacuum system, and the needles. That would be pretty much it for our quality control problem. If you're having a quality control or precision problem. That right there, you should have seen your problem at this point.

I'm making the assumption that you have changed the syringe tip, which would be the number one thing for quality control, or precision problems. (Camera pans to computer, :29)

I am going to escape out of this program. (Screen change, :34) And now I am going to the endurance. Hit endurance. (Narrator selects, “Endurance” from menu, :39) (Screen changes, :42) It doesn't matter; it's just asking you do you want it to run 24 hours or so.

Do I want the counter reset, that's a counter that's on the program that tells you how long endurance has ran for. If you hit yes, it's going to zero it, if you hit no, it gives you the last count. We're going to hit yes. I don't really care.

What it does at this particular time, it zeros the instrument. Let's go back to the instrument. (Camera pans to STA Compact, 1:07) When the green bar is going across the bottom, this is where everything zeros. It goes to the home position.

If something should fail in there, the arm doesn't go to the home position. Arm two doesn't go, it's going to stop right there, and for trouble shooting purposes, if it does do that, go to the last thing it did. This is one of the reasons we're running this program, so you can see the sequencing. (Machine begins to preform tests, 1:35)

Right now arm number two is picking up cuvettes. The cuvette loader just went over to pick up another cuvette. Needle one just got done purging, needle two is purging now. And it's going to go up, by the way, notice you might needle two doesn't go all the way up to the home position, that's normal. Do not worry about that.

I'm not sure you can see that. Needle number three goes up. Okay, so everything is just washed. My blue bar is all most there, it's done. Now we're starting the endurance. What it's doing, it's just now picking up a sample. Needle number one, now it's going to dispose of that sample, then it's going to go into the wash well and do the cleaning.

Now number two is going to do it. That's picking up reagent. Notice how the arm goes completely down. (Drawer one opens, 2:25) The needle goes in. It should not hit the sides of it, it never does. I've never seen it anyway. (Drawer one closes, 2:31) Then it's going to wash. The doors open, arm number two picks up a cuvette. Now arm number one is picking up a sample. Deposits that sample into the cuvette, washes.

Arm number two is going to pick up a reagent. Notice how it goes all the way down. That's the mixing of the sample. It should not hit the sides. Drawer number two is opening. (Drawer two opens and closes, 3:01) This will do this for 24 hours, by the way, assuming that it has no problems. Just loaded another cuvette, arm one is
picking up another sample.

Deposits that sample, washes, now picking up another reagent. See that pause there. That pause in theory shouldn't be there, but they do once in a while. If it ever doesn't go down, even if you see it once, that is an intermittent problem, usually it's either liquid in the line, or your detect cable is bad.

But, the bottom line is this. That needle should go down to the bottom of the reagent tray. Another thing that will cause that, is a motor, if that gear is slipping that motor sometimes will cause that. You'd be having gripping problems, well not gripping problems, you'd be having needles crashing.

Now needle number three is going into the wash well. I've got a problem there. That is my problem in this particular instrument. Needle number three is bent. The needle must be bended, check the needle number three. (Camera zooms in on bent needle, 4:22)
And of course you can see that the needle is bent.

That's a mapping issue more than likely. And now we're going to go onto the mapping. For the most part, that's it for the endurance. Hopefully you've got an idea how that runs. It will continue, if this would have passed, it would have continued on its cycle by loading cuvettes into incubation spots and then moving it into measure, and then eventually the measurer would be taken and put into waste. That's it for this session.