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avatar: cbarback
cbarback
11 posts
Replied to cbarback's post on February 1st, 2018

Hello all,

I have an LS6500 that I'm trying to get up and running.  According to stories, the power supply failed.  I had a new power supply installed, connected all the leads and here is where things go wrong.  The machine has a single S+/S- connector, while my PS has two, labeled V1 and V2.  The guy who installed the supply told me just find  way to connect both the V1 and 2 connectors to the S+/- lead and I'll be good to go.  I have created a connector to do just that, but have also tried just connecting on or the other V to it.  Either way, with the connection in place, it won't start.  The PS cuts out almost as soon as the switch is flipped.

I though maybe since it's just supposed to make sure the right voltage is applied to the wire, I could get away without it and here is my second issue.  Without the S+/- connector on, the machine seems to start up.  I don't see anything on the terminal, but the LED startup sequence begins.  but it seems to sit at the front end board test, and then reset.  It runs through the same sequence as before, somewhere in that sequence, the terminal beeps, and then it sits at the board test again.

Any ideas on what could be wrong and if I can get past this without paying someone to do it for me?

Many thanks in advance!

avatar: dpkleessr
dpkleessr
1116 posts
Replied to cbarback's post on February 1st, 2018

Please attach pictures of what you are dealing with.  Was this a Beckman Coulter engineer that told you that or a 3rd party engineer?  I worked on the LS6000/LS6500 counters for over 20 years and even I'm not sure exactly what you are dealing with but I will try to help as I actually was a factory trained engineer as well as an instructor for teaching on the LS6500.

Don

avatar: cbarback
cbarback
11 posts
Replied to dpkleessr's post on February 2nd, 2018

Hi Don,

Thanks so much for the reply.  Regarding the engineer, he was 3rd party.  Since it seemed like a quick swap of the power supply, we decided not to go direct to Beckman Coulter.  As for pictures, I hope the following will help.

This is the S+/- connector coming from the LS6500.

And here is the connector on my new power supply.  YOu can see that there are two S+/- positions, V1 and V2.

Next, here is the board with the startup sequence LED's.

And here is a closeup of the LED's in question.  The startup sequence LED's are on the right, and the left is a bank on which ones for Run and DIAOP are steadily illuminated.

This is the sheet on the inside of the front panel, listing out the meaning of the sequence.

The sequence of lights from startup is 1, 2, 5, 6, 6&1, 6&2, beep, 7, hold for a while, reset.  I interpret this as: U52-53 ROM Test #1, U26-27 RAM Test #1, U52-53 ROM Test #2, DSP Init & Test, DSP ROM U2-U3 Test, DSP RAM Test, beep, Front End Board Test, hold, reset.

There is another set of LED's on another board that lights up, steadily indicating Right Trigger Flash, Left Trigger Flash, Live Time Running, and Count Running.  I have pictures of these LED's and their info sheet, too.

I hope this is useful.  Please let me know if there is anymore information I can provide.

Thanks,

Chris

avatar: cbarback
cbarback
11 posts
Replied to cbarback's post on February 5th, 2018

Anyone have any ideas?  Thanks, all!

avatar: dpkleessr
dpkleessr
1116 posts
Replied to cbarback's post on February 5th, 2018

Sorry but I have been involved in a bathroom make over but I will take a look at what you sent and try to help you out later tonight.

Don

avatar: cbarback
cbarback
11 posts
Replied to dpkleessr's post on February 5th, 2018

Thank you so much, Don!

avatar: dpkleessr
dpkleessr
1116 posts
Replied to cbarback's post on February 5th, 2018

I'm waiting on a callback from one of my former coworkers about the wiring on the new power supply assembly that you now have.  Do you see the LED's on the relay board mounted on the power supply indicating the you have +/- 15 volts and +5 volts?  The +5 volts is obviously there as the diagnostic startup LED's are working but not sure about the other LED's.  It is also not uncommon for the diagnostic LED's to sequence a time or two but they usually end up with a pattern that can be interpreted once they stop sequencing.  Whatever that pattern is will tell you what the defective component is and from what I reread it appear you may have a front end problem but please correct me if I am wrong.  The loss of the +/-15 volts would definitely cause a front end issue.  I will get back to you once I hear from my friend and please respond to my questions.

Don

avatar: cbarback
cbarback
11 posts
Replied to cbarback's post on February 6th, 2018
Thank you, Don! I'll check those things as soon as I get into the lab in the morning.
avatar: cbarback
cbarback
11 posts
Replied to cbarback's post on February 6th, 2018

I just checked on the LED's you asked about.  The +5 and +15 ones are fully illuminated, but the -15 and also the +24 appear to be only partially illuminated, about 50% as bright as the other two.  No other LED's on that board appear to be lit.  The sequence of lights on the other board remains unchanged, but the DIAOP LED no longer lights up.  RUN still does.

And yes, the sequence hangs and restarts the front end board position.

Thanks, as always,

Chris

avatar: dpkleessr
dpkleessr
1116 posts
Replied to cbarback's post on February 6th, 2018

Do you have a DVM to actually measure the voltages?  If what you are seeing is indicative of a problem with those voltages then you may still have a power supply issue and that would stop the FRONT END from starting up properly.  The DIAOP LED should NOT be on all of the time.  That would indicate that the diaphragm assembly would be open all of the time.  The ONLY time that LED should be on is right before the elevator is getting ready to raise or lower a sample into the detector assembly.

I am curious as to why the 3rd party engineer did not install and verify the operation of the LS counter after replacing the power supply before leaving your lab.  That is very unusual.  Still waiting on a callback so I will get back to you as soon as I hear from him but let me know about the actual voltage readings.

Don

avatar: cbarback
cbarback
11 posts
Replied to dpkleessr's post on February 7th, 2018

Sorry for the delay, I had to find a multimeter from another lab.  I'm not very well versed in these things, so hopefully I did this right, but I tested the voltages between the specified voltage terminal and COM terminal on the PS.  The -15V read at -13.5V, and the +24 read at +22.8V.  I tested the others, too, and they were all pretty close to what they were supposed to be.  I'm not sure what the tolerances are for these things, so maybe that's not close enough.

As for why the engineer left without checking it, the answer is a mix of money and expertise.  He was contracted only to find and install the PS, since that is what my PI thought the problem was.  It seemed correctly installed, so he said he could try to diagnose the problem, but it would cost us just as much again and he wasn't even sure he could identify the problem.

It's not a great situation, I have to admit.  Hopefully we'll learn something from it...

Anyway, I hope this info helps!  Thank you!

avatar: dpkleessr
dpkleessr
1116 posts
Replied to cbarback's post on February 7th, 2018

I'm a little concerned about the -15 volts being 10% low and more importantly about the connections on the power supply.  My friend still has not gotten back to me but I will be trying to call him again a little later tonight.  What exactly is the +5 volts reading?  It has to be at least +5.1 volts because there are some cabling losses to deal with going to some connections that have lots of wire attached between the +5 and some of the modules.

In my 33 years with Beckman Coulter I ran in to competition with 3rd party service groups that made claims about being "factory trained" yet could produce no documentation to support that claim.  Installing the power supply is quite simple but not knowing how to properly connect it is quite troubling.

Anyway, I will get back in touch with you as soon as I sort it out with my friend but right now, based upon the LED pattern you said the Front End assembly looks to be the problem.  

Don

avatar: cbarback
cbarback
11 posts
Replied to dpkleessr's post on February 7th, 2018

Thank you, Don.  I checked the +5 terminal, and it's unfortunately reading 4.71.  So, that seems like it might be part of the problem.  If I'm correct, isn't that the exact sort of thing the S+/- connection is supposed to handle, ramping up the power if need be?  The fact that the machine won't start with it in place seems more worrying now.

I'm looking forward to hearing your friend's input.

--Chris

avatar: dpkleessr
dpkleessr
1116 posts
Replied to cbarback's post on February 7th, 2018

What I see in that picture of that connector is totally alien to me.  The old power supply never had anything like that on it and I had been working on them from the day they were released for sale back in the late 80's.  Hopefully he will answer the phone.  By the way, the +5 volt adjustment on the old supplies was located on the side of the power supply and you used a long, thin blade screwdriver to access the potentiometer through a hole in the metal chassis.  Frequently when making this adjustment it was possible to have the entire supply go off line which required shutting the power down and restarting it.

Don

avatar: cbarback
cbarback
11 posts
Replied to dpkleessr's post on February 7th, 2018

Yeah, it's a totally different connector to the original one, hence why I had to make a homemade bridge between them.  It seems strange that the connector would change an the purpose remain the same, but I don't know anything about the engineering that goes into these pieces.

I'll take a look tomorrow to see if I can find that adjustment screw you mentioned on this PS.  If so, I might try tweaking it upward ever so slightly.

--C

avatar: dpkleessr
dpkleessr
1116 posts
Replied to cbarback's post on February 7th, 2018
You definitely need it set to 5.1volts to account for cabling losses. Just exchanged texts with my friend so hopefully getting a call back in a little while. Don
avatar: dpkleessr
dpkleessr
1116 posts
Replied to dpkleessr's post on February 9th, 2018

I heard back from my friend and he said that they received NO service memos on the new configuration power supply so he will be no help on that one.  There is one other person that I will try to get in touch with to see if he has had any need of dealing with the new power supply.  Let me know if adjusting the +5 volts has had any impact upon the LSC's operation and I will do what I can on my end.

Don

avatar: cbarback
cbarback
11 posts
Replied to cbarback's post on February 9th, 2018
Thanks, Don. I'm still trying to figure out just how to adjust the new PS. It says it's adjustable on the spec sheet, but I can't find a place to actually make that adjustment, and no manual online yet. I'll keep looking and get back to you when I have more news.
avatar: dpkleessr
dpkleessr
1116 posts
Replied to cbarback's post on February 9th, 2018

Can you send me a copy of the spec sheet since I have never seen that power supply before?  Even if you take a picture of it would probably work assuming that it is only one page.  I might be able to figure something out of the diagram.

Don

avatar: cbarback
cbarback
11 posts
Replied to dpkleessr's post on February 12th, 2018

Sure, Don.  Here's a link:

https://www.mouser.com/ds/2/260/r755_3-3594.pdf

Let me know if you find something useful.  I'm running out of ideas.

--C

avatar: Chaos32
Chaos32
1 posts
Replied to cbarback's post on September 26th, 2019

Hi just wanted to follow up on this thread.... was there any progress made with the power supply swap?

I've also had to change out a power supply but the issue i'm having is that the LED sequence doesn't occur.  All the LED's are off.  But the RUN blinks and the DIAOP is on as well.