Discussion Category: Centrifuge
Unit will no longer power ON
We've had the 5415R for many years. It seems that no one in the lab ever turned it off (it has always been ON). Well, I turned it off and unplugged it the other day in order to clean the rotor.
Now it will not turn back on. I've tried replacing the fuse (slow blow 6.25A, 250 V), but that did not work.
Is there anything else I can check? I did notice that the fuse holder had positions for two fuses, but only one was occupied (I tried putting in two, but could not get everything to fit back in when two were in place).
Thanks for your attention and help!
Reply byThanks to this thread I have repaired many "No Power" issues by putting a 47uF Cap in place of the 22uF Cap.
The other problem this machine has is that "Lid" error happens at about the same age as the "No Power" problem.
I found that by taking out the lid lock assembly (two screws w/ long screwdriver), being very careful unhooking the motor power (hook up same way, carefully and same color). Take the motor loose from the locking frame (there are 3 screws). Take gearbox apart (two screws) use a little machine oil or light white grease to lubricate gears. Hook to 5VDC power supply and run in both drections for an hour or so. Put the unit back togeather. It seems going back and forth and not doing 360s w/ the gear box wears only a small part of the gears (gets in a rut, causes sticking).
I have fixed quite a few of the lid error problems this way. The 5415D is an excellent machine and will last a very long time by replacing the cap and running the lid motor w/ some new grease.
Reply byHello everyone. I'd like to start by saying thank you to some of the contributors here. Bill Beaty I couldn't have gotten anywhere with this without your detailed report on your University of Washington site. But here's where I am at currently with a 5415D: I am also having an issue with error 17. I had one laying around at my work that wouldn't power on. I replaced the 35V 22 uF, 25 220 uF, and 25V 330 uF capacitors. Now it powers on every time but still displays Error 17. The LM7805 voltage regulator near the LCD display ribbon cable is giving the correct output voltage at 5 VDC. But the LM7805 by the UC2844A pwm controller is giving me an input voltage of ~ 3 VDC and output of 0.7 VDC. I decided to check AC Voltage as well on this regulator and for input and output observed 5 VAC and 0.9 VAC, respectively. I found AC voltage across the 35 V 22 uF cap as well. Now I am not an electronics specialist by any means, but I know for a fact that the LM7805 isn't meant to handle AC voltage. So there's definitely something going wrong upstream. I still haven't replaced the power supply filter cap 250V 560uF. Could it be that it isn't filtering the AC voltage correctly? I decided to order a replacement. I also figured I'd order a new bridge rectifier KBU808 (and a LM7508 for good measure) under the theory that if I am finding AC voltage at this TO-220, there's something going wrong with AC/DC converter portion of the circuit. Could someone let me know if I am missing something? I'm not looking to send this out for repair as it isn't worth the money. You can buy these used on eBay in good working condition for $400-500 bucks these days. But any help would be greatly appreciated!