Chromatography Forum

I have noticed that sometimes the oven flaps on one of our 6890s is not closing all the way when the oven is heating. The flaps open fully when cooling and close when heating but do not appear to be fully closed, either during isothermal operation or during a program. I have received "oven not ready, temp XX at YY min" error messages the last couple of times in runs. The fan is operating properly.

Is it possible the flap doors just need adjusting or should the flap motor be replaced?

I've replaced the oven flap motor on both 5890s and 6890s for that reason, pretty straightforward repairs. I've also had one where the round oven flap had become disconnected partway, and I drilled a hole and installed a rivet to hold it in place (a screw and nut would have worked just as well).

In general, during the heating or isothermal mode (unless it's cooling down) if you feel hot air coming out the back, you know where the problem lies.

I show part number as G1530-60945 for the 6890 stepper motor, was under $200 last time I bought one (2006).

I agree with CPG. I've had to exchange three of these motors on 5890 6890s in the last few years. I bought one earlier this year, and I think the price was up to 245$.

It's easy to change the assembly, shouldn't take more than 10-15 minutes or so. Also, remember to just loosen the bolts on the housing, and take that whole vent off...much easier than trying to take the motor out while on the instrument.

Agreed. This is the first thing I would replace.

We always keep these on hand.

We always keep these on hand.

I stock one for a 6890 and one for a 5890.

Yeah the stepper motor is a pretty common thing to go, thankfully it is easy to replace/cheap as others have said .