Chromatography Forum

Sounds like you're doing some good troubleshooting. Good luck getting to the bottom of it!

I'm still confused about how to check the oven door mechanism.

Mea culpa. I had thought there was an actual switch there, but I got into mine last night to find out I was quite wrong. My apologies.

The best I could do was reproduce the error by leaving the door ajar, resulting in an inability to ramp the temperature up fast enough, so- nothing new there.

There is diagnostic/tuning mode for heaters (entered pressings [Stop] during boot) or using [.] commands (can not remember exactly).

When mainboard lost PID constants for heater - you can get such problem.
Try to re-calibrate oven sensor and heater.

Try to re-calibrate oven sensor and heater.

And for those playing the game at home, that's on page SVC 5-29:

https://www.ursinus.edu/live/files/140- ... -manualpdf

Thanks for the further replies.
the oven and other temperature sensors measure room temperature reasonably.
I can only do a one point (re)calibration at room temperatures, since I can't heat up the oven.
I adjusted delta T by 0.1 K.

It didn't solve the problem.

Thanks for the further replies.
the oven and other temperature sensors measure room temperature reasonably.
I can only do a one point (re)calibration at room temperatures, since I can't heat up the oven.
I adjusted delta T by 0.1 K.

It didn't solve the problem.

Does the oven thermal sensor show adequate value when you heat it with the solder (~350C)?
Does the value increase monotonically when you heat the sensor or jumps?

Currently the main PCB is removed from the GC so I can't observe the readings. I will respond on that as soon I replace it.

*** Update
We put the 5890 Series ii board into a working 5890 series i and could reproduce the error:
Oven not heating
Fan not running.

While playing around with the working 5890 series i and it's original main PCB, we found out that the contactor on the Power PCB in the back of the GC (picture on post from DEC 7th) gives a physical response to entering a temperature on the keypad. It clicks and creates a contact, you can both see and hear it. Again, as posted earlier, this contactor is main PCB controlled.

Right now, we are hunting for a replacement board, since this test again hints towards a main PCB issue.

I will give an update.

Right now, we are hunting for a replacement board, since this test again hints towards a main PCB issue.

I've got a fair amount of used 5890 parts from working units which were disposed of because they were no longer needed. Reasonable too, if shipping to within USA; but I can only do PayPal, money order or check, no credit card.

Post the part number(s) of what you are looking for, maybe even a photo too, along with your E-mail address. I'll post if I have that part, and I'll send you an E-mail asking you to make an offer.

***update

swapped in replacement mainboard - system back running, no FAULTS, all heated zones get powered up.
visually, the faulty mainboard looks totally fine.

thanks for the offer KM-USA, unfortunately I read it after hunting on ebay. We have 3 5890s running, so who knows, what comes next.

Thanks to everyone for the steady support. I'll probably give another performance update after a couple of weeks.

We have 3 5890s running, so who knows, what comes next.

Three operating 5890 units? Maybe buy his entire stash of parts.

Glad to hear you finally got to the bottom of it. Thanks for the update!