Thermo Fisher Scientific Jouan B4i Series
Q: I have recently repaired one of our centrifuges. I changed a slow charging resistor, 15VDC Voltage source and some connectors. I have given it a go at different RPM levels, it is turning, everything looked fine. Then, I got a call from the lab assistant. She is saying that rotor turns, but we can’t separate the samples (blood). What could be the cause of this? Are there any things that I might do to fix this or is it them doing something wrong?
A: Perhaps it is braking too fast, causing the separated fluids to re-mix. Check the braking function/setting. Or maybe, if it is taking longer to get up to speed, they will need to increase the program time. I would recommend that you try increasing the time, as a quick possible solution. Have you checked speed calibration at the speed they are using, with the rotor they are using?
A: This is a speed or time problem. The lab is using a specific tube which requires a specific speed at a specific time. The lab should be able to tell you what the tube manufacturer requires to get the separation required.
A: How much does the centrifuge shake when going up to speed, at speed and while braking? With a swinging bucket rotor, sometimes the buckets don’t swing out or fall back down evenly. Of course this creates an imbalance situation that could remix your seperation. The usual fix for this is to remove the buckets and clean the rotor pins where the buckets sit and clean the bucket contact points where they meet the rotor. Sometimes as the rotor is stopping right at the last minute before it actually stops you might hear a squeak when the actual bucket that isn’t falling back into place with the others falls into place. I hope this helps. The other suggestions are good as well.
Leica – CM1510 S
Q: The electrical advance and return buttons are not working. The motor runs when hotwired to a 24V supply. The cable to the motor delivers 10V. Maybe this is correct, maybe not. I suspect a problem with the microtome part talking back to the circuit board. Documents include a service manual for the CM1510, but not for the CM1510S and the board I have looks very different. I would like advice on how to check the functioning of the circuit board and how to order a replacement.
A: Could be the switch. I’ve had to replace switches on these in the past. My notes show: large coarse advance/retract switch for 1510S: 14682203001. It says $24 each 2 in 2016. I think I might have had to replace a fine advance switch at another time, but I can’t find that part number, at the moment. However, if neither the fine or coarse advance/retract switches work, you might indeed have an electronics board problem. My advice would be to send the board to a PCB repair facility to see if they can evaluate/repair it. I have had good luck having several boards repaired, for a few hundred dollars, when the replacement boards were not available, or would cost thousands to purchase new.
A: Call Leica Biosystems at 800-248-0123. You’ll probably need to create an account, before you can order anything. And, knowing the part number is essential. They aren’t forthcoming with help on finding part numbers anymore.
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