Zero counts

Finally back to working on this.  Pulled PMT base assembly out and cleaned everything up.  Put it back together and when I power it up the system start up LEDs stop on the CRT Terminal Test.  The display on the Wyse thin client shows the full screen white/yellow Wyse logo, then v4.6, then Wyse WinTerm, ica/Citrix, and finally a long white bar at the bottom of the screen.  The printer stutters for a second at the end of all this.

I've checked to be sure I didn't knock something loose removing the PMT cables.  I do have one plug that's not connected to anything where I was removing cables; it's J515, but I can't see anywhere it night go.

There is apparently another one of these on campus being saved for parts.  I'll try to track it down and see if I can borrrow some pieces for troubleshooting.

Any reason for the Wyse to suddenly fail?

Rob

Hopping over from what started as a 'WYSE Terminal' post as that problem has been resolved but current problem seems to be PMT related. 

Don, to continue where we left off, I'm comfortable with instrument repair and troubleshooting this further, especiallyif there could be simple solution. I saw previous post about a piece of debris causing something similar, I did not see anything (assuming I was looking in the right spot, I was looking at the area right where a vial gets pushed up). 

Regarding some of what was mentioned earlier in this thread, I am seeing something similar related to the DS1 and DS2 lights. Seems like DS2 is lit all or most of the time and DS1 only flickers on for split second about the time a vial is lifted. Assuming the two connectors going into this box are the PMT cables. With both of these cables disconnected, DS1 and DS2 are both lit. I did not try swapping positions as the previous poster did.

You previously mentioned 'light shock', how would this occur? I did have the front cover off yesterday prior to receiving the new terminal. Although I assume if that caused light shock it should be resolved by now? 

LG1, you[re right about those cables coming from the PMTs.  Swap them and see if the LEDs switch places.  You can also try swapping the HV connections, just to be thorough.

Funny that you're problem has gone from terminal to PMT, mine the other way (although I think I've still got a PMT problem).

Rob

Hi Rob,

Yea, funny it's reversed. I tried swapping the PMT cables and the LEDS reversed - DS1 on, DS2 off. Wasn't sure what you meant by swapping the HV connections. 

Did you ever get your issues resolved?

Swapping out the PMT signal cables and getting a swapped out LED response is indicating which tube/socket is likely the source of your problem and rules out the front end board as being a part of the problem.  Without having replacement parts available to you makes determining whether it is the PMT or the socket that is at fault.  PMT's by themselves were the most expensive replacement part I ever replaced in an LS counter but that was due to an internal pricing issue within Beckman Coulter that they refused to correct.  You may be able to find PMT's at a much better price point by going to someone that acts as a reseller of the PMT's.  The PMT sockets are much more problematic as they were exclusive for the LS counter and they were not cheap either.  A 3rd party service group or even Beckman may be able to help you out because neither the socket or the PMT are repairable.  As to swapping out the High Voltage connectirs on the HV Power Supply, I only replaced 1 or 2 of them in the 23 years that I worked on the LS6000/LS6500 series counters and they were for outright failures as opposed to only 1 side of the piwer supply board failing.

Don

Light shock takes place when the PMT's get exposed to fluorescent or sunlight and it literally can take a day for the tube(s) to calm down enough to get normal counts or even a valid calibration.  It is always best to work with the PMT's under red light conditions.  I had a headlight with red LED's on it that I used when working with the PMT's in a dark room.  Not really a part of your attempts to fux your problems but some perspective on how to safely work with PMT's.

Don

Okay, so information so far is indicating 1 bad PMT/socket, other PMT and front end board likely okay? 

In your experience, more likely to be the PMT or the socket? And if I were to get my hand on a replacement, how involved is it to switch one of these out? Also, we have an old LS5801 here, any chance parts are exchangeable?

Regarding light shock, does this happen when front cover is off? And is it enough to result in 0 CPM?

First, light shock only happens when the PMT's are directly exposed to light such as when you are actually working to replace them and not by just taking any of the covers off of the counter. Next, there are NO major electonic parts that are interoperable between the LS 5800 series and the LS6000/LS6500 series counters. Finally, replacing a PMT is not difgicult at all and takes very little time but it does require careful handling of the PMT itself. The PMT socket replacement is much more involved as it requires taking the center rear panel off in order to get easy access to the cabling which is zip tied along its length and there is a LOT of cabling to deal with. I would be VERY careful purchasing replacement PMT's on line UNLESS they come with some performance guarantee. You will only know that a PMT is good, assuming the PMT socket is functioning properly, when you place it into the counter and power it up and then try to count samples or calibrate the counter and you MUST recalibrate the counter whenever a tube, socket, or front end board are replaced.

Don

Okay, sounds like something we'll just have Beckman do. Just wanted to make sure I wasn't missing something simple.

For estimating the repair cost, would you agree it sounds like 1 PMT and/or socket is bad but the other good? Also, just for my knowledge, am I identifying the PMTs correctly in this picture? 

https://drive.google.com/file/d/1uBFxbDP2F-Im_j6q9eEGNgTMTIF7_bAJ/view?usp=sharing