I am having the same problem right now and not sure how to fix it. Did you ever find a solution?

It showed that the valves are blocked, after replacing that it turned into normal. But Today I found there is another problem.

The machine runs OK -- sample taking, collection and recording. But I found that AT THE BEGINNING OF sample running, there are significant amount of fluids back into the sample tube. The student in my lab has to run the same samples at six different time points, the sample size was found to increase from 500 ul to about 800 ul. UNBELIEVABLE. Anyone know what is the problem?

Hi Huiping Yang ,

Are you using sheath fluid or deionised water? This machine does not require sheath fluid and we have found this causes crystalisation of the connection points. Deionised water is recommended in the C6 manual - try this and it may stop blockages.

Many thanks,

Matt

same problem here.sigh

Hi Huiping Yang, I've been following the posts on RG of your experiences with the C6. I have had this exact problem - fluidics stability error message', and back flow through the SIP during start up, sample collection and shut down - several times now, albeit on C6 Plus. The first time it happened it, my instrument was a little over 3 years old, but just out of warranty and no service contract coverage. I bit the bullet and shipped it to BD for assessment and repair ; before shipping I was told to expect ~$4k, but after shipping and factory assessment, the repair cost $23k; Reluctantly, I paid it and the repair took ~4 months. We got it back just before COVID closed the lab, and only ran about a dozen samples, where it ran fine. When we returned about 4 months later we had the same series of problems about presumably due to improper long-term shutdown (BTW, there is no long term shut down protocol in the manual). Since I cannot afford another $23k repair, so I set about trying to isolate the problem myself, as there is nothing to lose at this point. I replaced all filters, fresh reagents filtered at 0.2um....no improvement. Tried all of the recommended cleaning (Hot water Flush, Hat Trick, etc); nothing improved. I set about manually purging all of the fluid lines and manually cycling the solenoids using a 12V power supply. Restarted, no change. I then noticed there was almost no fluid coming out of the waste line after several cycles of shutdown/restart, and that where was pressure built up in the waste line, suggesting a blockage downstream of the waste peristaltic pump. Working my way back up from there I think one particular solenoid is clogged/dirty/failing as that seems to be the common intersection between the waste outlet of the flow cell and the peristaltic pump. I was able to clean out this solenoid by flushing it manually, and got it working again (waste flow returned to normal at medium or high flow rates, but not low flow; also would not pass QC). Using counting beads at med and high flow, everything seemed ok, but low flow would have the fluidic stability error. Right now, I'm thinking it could be that one of the pressure sensors is bad but I'm pretty sure this solenoid is failing again. Unfortunately, I could not identify a replacement. I contacted The Lee Co, who makes the solenoids, but they say it is a 'custom' part they cant sell, and that I would have to get directly from BD. None the less, I might buy a 'similar' part from Lee and see if that works. I'll post back if I get this figured out, but I would not recommend buying the C6 Plus, if they even sell it any more.

Hi Jason A Horton ,

We had similar issues with the SIP filling before sample collection. Just to check, what are you using as your sheath fluid? A common misconception is to use sheath but the recommended sheath is 0.22 um filtered, deionised water. This should hopefully reduce blockages. Also, what valve board does your c6 have? I know there were issues with the old style valve board and these can be replaced by the new GEN II type which will help with reduced backflush into the SIP.

Other things could be the sheath and waste dampener being corroded inside or the sheath pump not working during the decontamination cycle.

To shutdown, we run sodium hypochlorite (5%) through the machine on a fast flow for 10 minutes. Then run 0.22 um filtered deionised water through the machine for 10 minutes. Then leave the deionised water on the SIP and hit the power button on the front. This has really helped with keeping the machine in good condition.

Hope this helps.

Matt

Thanks Matthew John Roberts ,

We've been using BD Sheath Additive (0.82% NaF, according to their MSDS), as our sheath fluid, but will try filtered DI if/when I can resurrect our machine. We also had been doing a similar shutdown, albeit only 5 min at each step. I'm not exactly sure which valve board I have now - mine was originally a 2016 model re-built in early 2020.

I'm in the process of doing a thorough teardown/cleanout, and will let you know how it goes, and will make sure to pay particular attention to the damper and sheath pump; I suppose the pressure sensors could be gunked up too, hence the fluidics stability error I'd been getting. Will let you know how it goes after the washout.

Do any of you know why the cytometer when performing the startup process immediately goes to automatic shutdown?the traffic light is yellow. I've already checked and cleaned the valves, the fluids are circulating properly. I will greatly appreciate your help.

its voltage is limited , i don't like that

Hi Jason A Horton, just wondering how is your machine working. I am running into the same kind of problem. Thanks