Beckman Optima L-90K errors

Excellent, Thank you Don.

If you do not hear back from me Friday please send me a reminder as I have a long drive home that day.

Don

Don, I hope you had/have a safe drive home. I am looking forward to getting this machine repaired.

Thanks

Sorry I could not get back to you yesterday but it was a long drive home and I really was not feeling well by the time I got home.

First, had the centrifuge previously been running normally before the errors started popping up?

The d6.3 error says that the drive is overheated. This comes from the sensor mounted on the bottom of the drive assembly. The service manual says that you will get the error if the drive thermostat opens during a normal run or is not deactivated within 5 minutes of power up. The signal goes up to the Instrument Control Board (ICB) to Pin 28 on J & P11. Normally this signal should be at a ground or low state. Rarely have I heard of the thermostat actually failing and I never personally saw one in decades of working on this series of centrifuges. Make sure that the single wire connector is properly attached to the thermostat sticking out the bottom of the drive. That happened to me when I had to have things disassembled and did not get the connector of correctly after replacing the shroud assembly. So, if it is not the thermostat then you are probably looking at and ICB issue and there really is not much you can do on that board with all of the surface mounted devices.

The d8.1 error says that you have a problem with the door latch which could be a bad micro switch on the latch assembly. The error occurs when the vacuum is supposed to be turned on and the door latch status says that it is not closed so that's why I would be looking at the door latch switches or the latch assembly itself. The solenoids do eventually wear out or physically get gummed up so the best way to deal with the latch is to remove it from underneath the top plate and watch the solenoid action when you tell the centrifuge to run. If the plunger does NOT pop up when you tell it to run then the plunger itself may be gummed up but something is definitely not right with the door latch assembly. And yes, this was an all too regularly replaced service part.

I hope this helps but feel free to get back to me with any other questions. Don

Hi Don,

I got back on this piece this morning. 

You were right about the thermostat wire, I couldn't see it until I removed the shroud. It was completely disconnected. Got it reconnected and that fixed that error.

I'm working on the door switch now.

Thanks for the help, I'll come back with whatever fix I end up with for the door switch.

So I found that the solenoid pulls the door lock down and that there is an internal spring that default keeps the lock up. Is there supposed to be something pushing against the internal spring from the bottom? The spring itself is nowhere near big enough to hold the door lock in the locked position. I've looked around my workspace and I didn't find anything that might have fallen out.

Possibly the old spring broke and/or was replaced by someone else and they didn't replace it with a big enough spring. So I looked around and found one the would keep the door lock in the lock position. I also cleaned the entire lock assembly and its surrounding area. This seems to have fixed the door error.

Thank you for pointing me in the right direction Don, you're a lifesaver.