When the org chemist is on vacation: MSD disaster

[MichaelVW]

Hi,

I've been poking around the forums a bit but this is my first time posting. The occasion is precipatated by an instrument going down while the guy responsible for it is on vacation. I have a rather basic understanding of how to run our 6890/5973... but my primary goal is to not break it more than it's already broken. Maybe someone here can help. This is a long story but the real question is about the pump more than the instrument.

The instrument was running fine on Friday. Saturday morning it was found to be almost out of Helium. That was changed, a couple samples were run that seemed to look okay, but Monday morning the instrument was found to be giving almost zero response. Trying to tune it produces what looks like noise. Running blanks gives extremely low ion counts scattered around the run. We think maybe a board was fried, but before we call out a service tech, I was asked to try cleaning the source (first attempt!) and giving it a go. That seemed to go alright, but when I got back there and plugged in the rough pump, the pump started belching a bit of gray smoke into the air. I let it run 20-30 seconds and it was still doing it. I've never noticed it doing that before. I spoke with my boss about it and we kind of figured... it's not worth using the instrument if we're worried about the pump. I mean, could the instrument end up flooded with oil or something equally bad? Or do pumps always do that for a while and we should just man up a little? This feels like a silly question but, again, I don't want to break anything. Did I mention our service tech is on vacation too?

[cleh]

You have a leak and it's probably at the analyzer door. Don't screw the two screws on the door down, hold the door tightly against the manifold with your hands so the door is flush with the o-ring. Turn the power on while holding the door. You will hear gurgling and see some smoke come out of the pump (this is the air being pumped out of the system). You will feel the door get pulled toward the analyzer and after about 30-45 seconds the pump should stop gurgling. You can then screw the front screw in but only finger tight. Don't screw the rear screw in. Good luck and let me know how it goes.

[MichaelVW]

Thanks Cleh! The pump gurgled and sputtered and complained for a while, but now it's humming along contentedly. The only thing now is that when I went in Chemstation to "Vacuum -> Pump Down" I got an error that said

"The high vacuum pump is not ready. Temperature control fault."

The LED on the instrument says "Pump Error See Host"

Maybe I just have to wait a bit longer?

[cleh]

Make sure the vent knob on the front is closed (forgot to mention that). Close down chemstation, turn the MS power off for a few seconds and then back on. Open chemstation and then select pump down again.

[MichaelVW]

Hm, chemstation is telling me the Quad is at 511 degrees... it's only set to 250. I was thinking of venting the thing and opening it up to make sure all the wires are connected right... but when I go to "vent" it says "System is in the VENT state (high vacuum pump off). Temperature control fault." So...

[cleh]

Yes, it sounds like the heater/sensor connections. You can power down and vent. The system is cool enough because it shuts the pump heater off when the temps aren't in range. You can call if you need help. We do free tech support and it may be easier to walk you through things on the phone (857) 277-9858.

[MichaelVW]

Thanks for all your help. The good news is that we were able to finally get it pumping down. The frightening thing is that when we finally opened up the chamber, thinking it was vented (the software seemed to be saying it was) we got a little wisp of smoke. Maybe pump fumes. So... we'll see what happens.

The problem was apparently two wires detached from the top left positions in the feedthrough board. (I want to say "I know I attached them!" but... if anyone else said that, of course I'd know they must have forgotten). And I'm told the position of the two green heater wires on the bottom left matter too... I thought they were interchangable.

You live and learn I guess.