Hi Ugyen Tobgay,

Does your error occur at the same point each time in your analysis or does it occur at unpredictable times like you implied? Did you try troubleshooting your DAD through the Agilent Lab Manager software?  Check to see if any of the detector tests fail.  If not, I'd check how long your lamp has been in use (vs its lifetime) and that the lamp/connections are all in order by opening the lamp compartment in your detector.  I use an Agilent 1290 daily and I've had some issues with the detector lamp turning on (when it was near the end of its life), but I've never encountered your problem.  Hope that helps.

Michael

The duration of the lamp is unpredictable, it goes off on irregular interval. After troubleshooting the DAD in-accordance with the lab manager software, i will put on the status of the DAD. For the current status, deuterium lamp was used for 1786.10hrs. 

we would like to thank you for your information.

what is your software is it chemstation or different ,if it is chemstation main problem lies with LAN connection pls look at this angle definetly your problrm will be solved correct the lan connection between hplc and lan

we are using chemstation software and we even reinstalled the software again. its been a month now, the problem still exists with no clues of software and hardware errors. i will try with the mentioned suggestion. 

we are even looking forward for more recommendations from the specialist in the field  to share their expertise which would greatly help us.

thank you Sekhar for your valuable information.

IS PROBLEM SOLVED 

its still giving us the same problem after troubleshooting, its confusing us.

you just change the detector to RAD and check .if problem doesnot come it can be concluded that detector DAD has problem and it should be replaced or rectified hope it works this time.

thank you Mr. Sekhar Reddey for your constant support and valuable information's. As far as or now, we assume it problem with the detector and if there is a possibility, we will change the lamp responsible for the error. If not we will try to seek more troubleshooting techniques and try to fix those errors. 

thank you so much.

hope you overcame the hplc problem

99% chance this is a very simple fix. Just replace the D2 lamp with a new one and the problem will go away. They are maintenance items and last a year or two. Depending on which bulb is currently installed, you have either exceeded or are close to exceeding the "normal" lifetime of the bulb. 1,700 hours use = time to dispose of the bulb.

• Note: After you install the new D2 lamp, please be sure and follow the software directions to reset the timer, then run a full wavelength calibration and intensity test BEFORE using it. This will calibrate the lamp signal and also provide you with a benchmark for the lamp under standard conditions (we recommend you fill the flow cell with pure ACN for the test). This will be useful in the future.

Thank you Mr. Bill letter. We are going with your suggestion.

we have installed new D2 lamp and calibrated the lamp, but still the same problem persists with no solution. what can be some possible ways to overcome the specific problem. i am just a master student and we dont have fund to replace the whole module.

your expertise and suggestions will benefit us a lot.

Did you look in the Instrument error log to see what message was posted when the DAD power status changed?

The power supply to the DAD could be damaged (very rare, but have seen it before). You must establish what conditions exist when the Supply goes offline. This could be software corruption for just the module or firmware corruption (did you try uploading the appropriate firmware to the DAD?). If it is a hardware fault, the log should show the appropriate error message. If it is power supply only and not firmware, then no message will be logged.

we used different HPLC machine for the whole project. Started everything from scratch and completed the project successfully . Thank you all for sharing your expertice