Chromatography Forum

Hi
I have an 2695 waters instrument. After the connecting are made, I tried to run a method. I get an error message saying "Absorbance detector failure". I am kind of lost. The detector light is on. The instrument runs in the flow mode but as soon as I try to run a method its shows the error. Any suggestions ?

thanks

Henry

Sounds like a configuration problem.

Try turning everything off (for 10 s or more). Then turn on all "peripherals". Last, turn on the "controller" - i.e., whatever component contains the computer that goes out and looks for everything else.

If that doesn't work, you may have to check that the software is configured to recognise all components. I've done this on Agilent instruments, but not on Waters, so can't help you there.

Henry,

I'm only familiar with the previous version of that instrument
but anyway a quite common problem at the start up is passing the
self-diagnostic of the PDA. A small air bubble can cause this failure
(even if you can actually have the lamp light on).

The solution is generally flushing the PDA at 2 ml/min with 100 %
methanol for 10-15 minutes and power cycle the PDA.
After 1-2 minutes you should be able to see if it worked out.

Regards,

bhuvfe

Hi,

Thanks for your suggestions. Incidentally, when I had turned on the flow mode with solvent running through at 1ml/min, there was not much solvent coming out of the PDA out connector. After tightening the screws on the inlet and outlet on the PDA, the solvent flow seemed to be normalized. So I am guessing that might have created a bubble ?
In addition, the other question was- the PDA was on for only 15 mins before I started doing all this- does that matter ?

Appreciate your helpful suggestion!

Henry

What CDS are you using? Empower or Millenium?

Then have a look at the Configuration-Module of the software and see if the systems and components are listed as "on" or "ok".

Maybe you have to check if you have configuerd the correct IEEE-adress (> 996@###).

An other issue could be some incorrect configuration of the "Instrument method" (eg. written before some modifications of the data connections or detector itself), but AFAIK in this case, you should not be able to select them in the "run samples"...

- open the Instrument Method and see if the component listing is correct and the components working as well

- try to setup or better monitor the baseline with the indented instrument method (run samples > selcet instr.method)
If the error occurs, try to make a new instr.method and try again.

- have a look at the PDA diagnostic (a menu within the "run samples" module) and see what the self diagnostic tests are saying for more informations (maybe to post here or tell a Waters service person)

Henry,

To answer your questions.

Probably you had a air bubble.

It matters. The PDA starts its self-diagnostic only when
you power cycle it. If at the beginning you had a bubble
whatever you do afterwards doesn't count.

Do you see a blinking light next to the LED of the lamp?

When was the last time you used the PDA?
What you described is quite common after a period of
long inactivity.

I got the methanol-flushing procedure directly from
Waters engineers and the long flushing time from this document

www2.faculty.sbc.edu/piepho/chem342/Waters_HPLC_Directions_'06.doc


If the flushing doesn't help check if you have a clean
cell (if not there's a cleaning procedure in the manual).

Hope this helps.

bhuvfe

Your reply to the problem makes sense and have made a note incase i have similar problems, however please can you explain what is meant by 'power cycle' Thanks and best wishes

Tilly,

Power cycling means turning an instrument off and then on again.


Regards,
bhuvfe

Hi Thanks for your replies. It turns out that the PDA detector is fine. I interchanges it with a working on from another instrument. It might be some softwatre configuration that I am currently trying to sort out.

Henry

Maybe you have to check if you have configuerd the correct IEEE-adress (> 996@###).

Did you check this?

Is your detector showing up in the instruments tab of the configuration of your node? (Configure system >
empower nodes > rightclick on your node > properties > instruments)

This check should point out wether it's a configuration or an instrument failure.

Ace

Thanks for the suggestion. I went into the software, all the IEEE-488 addresses look fine (PDA-2, HPLC-4). I am using a GPIB interface card to connect the IEEE-488 cables. One goes from the computer to the HPLC and then to the PDA. Not sure if I need contact closure as I am controlling the detector with the software. I also tried the contact closure method- connected the B- (1 an 2) to the PDA (Event in 1 and 2), no luck with that either. The voltage coming from PDA (Event in 1 and 2) was about 5mV so it would suggest that Event in from PDA should go to the HPLC (B- 1 and 2).

Henry

Are you using Empower or Millenium?
In the instrument tab of your empower node, is your PDA OK after you click scan instruments?
I don't think you need the contact closures, an IEEE cable from HPLC to PDA should work fine.


Ace

Hi

I am using mass lynx. I have had other folks who use Empower system and they don't need a contact closure either. can see that the software detects all the instruments and is ready to make a run but when the run is started it seems that the HPLC is unable to talk to the PDA and give th adetector fault.

Henry

Does your instrument method contain the correct instruments? Does it have parameters for a 2487, a 2489, or other detector that it can not find in the configuration when it tries to set the instruments up. Have you tried to just pick the instrument method and then click on set up, in run samples, to see if it works there?

Good point. I will try that and also maybe prepare a new method and load those, that might help to erase any previous settings that it might refer to.

Henry