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avatar: Bills lab
Bills lab
6 posts
Replied to Bills lab's post on January 10th, 2017

When we turn on the power for the J2-21, the power seems to start and stop  - as if i was turning it on and off every second.  Any idea why this might happen?  

avatar: dpkleessr
dpkleessr
795 posts
Replied to Bills lab's post on January 10th, 2017

Is the main power cycling off and on or is it the compressor turning on at power up and then shutting off? It is normal for the compressor to come on momentarily and then shut off at power up and part of that process is determined by where the temperature is set to run at. Please get back to me and let me know more clearly about what is going on.

Don

avatar: Bills lab
Bills lab
6 posts
Replied to dpkleessr's post on January 10th, 2017

We're not sure whether it's the main power or the compressor. When we flip the  power switch, the LCD lights up, then the compressor attempts to start, sputters for about 1second, and then everything shuts off before attempting to start again. We have been unable to change the temperature it is set to run at as the LCD/control board power fails before we can change the temperature setting.

avatar: Bills lab
Bills lab
6 posts
Replied to Bills lab's post on January 10th, 2017

Also, the last time it was used the temp was set for -4C.

avatar: dpkleessr
dpkleessr
795 posts
Replied to Bills lab's post on January 10th, 2017

OK, you posted this under the much older J2-21 centrifuge link which does NOT have an LCD panel so exactly what model of centrifuge do you have? I sounds like an Avnati JI model centrifuge if it is a floor model centrifuge but you will have to be more specific.

Don

avatar: dpkleessr
dpkleessr
795 posts
Replied to Bills lab's post on January 10th, 2017

Considering that you were probably running a liquid sample, why would you be running at -4 degrees?  Frozen samples can cause major problems both for the sample itself as well as the rotor.

avatar: Bills lab
Bills lab
6 posts
Replied to dpkleessr's post on January 10th, 2017

Sorry for the confusion. It is a J2-21M.   Its printed right on the instrument.  Not sure what the 'M' means and if that's very different.  

I didn't mean specifically an LCD panel, just the lighted display panel.

 The -4 degrees C is correct. The samples (which are lilquid) are only in for a few minutes with this specific run,  and they don't have enough time to freeze.

Thanks so much for helping with this! 

avatar: dpkleessr
dpkleessr
795 posts
Replied to Bills lab's post on January 10th, 2017

OK, that helps a lot. So, does the centrifuge power cycle constantly? Do you get any of the LED's in the display lighting up at all and are they staying on? Does the touch panel function at all?

Don

avatar: Bills lab
Bills lab
6 posts
Replied to dpkleessr's post on January 10th, 2017

When I turn it on the orange light of the 'power' indicator stays on the whole time.  The red letters of the display appear with the previous settings for speed, min, and temp, and remain visible for about 1.5-2 seconds, then quickly flash off, and come back on for another 1.5-2 seconds and the cycle continues. The touch panel does not respond even during the 1.5-2 sec that the letters are visible.

 I can hear and feel the lock for the chamber door alternating engaging/disengaging every second or so.  In order to open or close the chamber door, I'd have to time it just right to coincide with what its on and that's how i can open or close.  

avatar: dpkleessr
dpkleessr
795 posts
Replied to Bills lab's post on January 10th, 2017

I will have to check my old service notes and get back to you but it sounds as if the CPU board is in a reset loop. Do you or someone you work with have access to a digital voltmeter and other service tools?

Don

avatar: Bills lab
Bills lab
6 posts
Replied to dpkleessr's post on January 10th, 2017

Oh man...  Yah we can borrow a digital voltmeter from the engineering department tomorrow - it's too late for today.  If this diagnosis turns out to be correct, do you think it's something we might be able to reset ourselves with the current CPU board, or would a new one be required?  

Much like a Ford pickup with 180,000 miles on it -  i'm at the point where i'm not sure I want to put any more money into her or simpy let her go super-cheap to a good buddy....

avatar: dpkleessr
dpkleessr
795 posts
Replied to Bills lab's post on January 10th, 2017

The CPU board in the J2M is the same type of board used in the L8M Ultracentrifuges which also had a problem similar to the one you are experiencing however the CPU board and the switch boards down below were the only common factors between the two. Again, I will dig out my manual and see what I can come up with but you may be looking at a board problem with little that can be done in the field.

Don