Chromatography Forum

Hi guys,

Just witnessed this problem with our old Agilent 1100 VWD. All the modules on the HPLC tower would initialize fine in Chemstation, but when the pump, column heater and VWD is turned on, the VWD would take a long time to initialize and eventually fail. Looking at the D2 lamp through the little port shows that power is going through the lamp (hence not dead) but it would shine bright, then dim significantly but to a steady faint glow, then shut off after 1 min or so. In addition, a weird phenomenon is that when the lamp error pops up, which says UV lamp failed to ignite, a "run" starts and the pump and column heater display turns blue. I don't think this is normally what happens when there is a module failure on the Agilent HPLC. Any ideas? Suggestions?

First guess is that it is time to replace the lamp. Normal lifetime is 1,000-2,000 hours. How many hours on this lamp?

We have an 1100 and two 1200s in the lab with VWD UV detectors on them. We have had the same issues. After consulting with Agilent . . . we believe it to be an issue with the ballast. http://en.wikipedia.org/wiki/Electrical_ballast

You might want to check that out as we were losing lamps early due to poor current regulation.

Yeah, don't know why, but Agilent VWD lamps take considerably longer to light than do the DAD lamps.

First guess is that it is time to replace the lamp. Normal lifetime is 1,000-2,000 hours. How many hours on this lamp?

I am actually not quite sure of this since it was an acquired unit from a company that did not need the HPLC stack anymore. My guess would be that it is past the normal life time. I will look into getting a new bulb just to test it out.

We have an 1100 and two 1200s in the lab with VWD UV detectors on them. We have had the same issues. After consulting with Agilent . . . we believe it to be an issue with the ballast. http://en.wikipedia.org/wiki/Electrical_ballast

You might want to check that out as we were losing lamps early due to poor current regulation.

Hmmm, does that mean I have to open the cover/plastic box of the VWD unit? Is the ballast easily replaceable by a normal HPLC operator, such as I, or would it require an outside tech and get charge a boat-load of $$?

Yeah, don't know why, but Agilent VWD lamps take considerably longer to light than do the DAD lamps.

Yeah I noticed that too. If I had an extra DAD unit I would swap out the VWD immediately......

I forget but Agilent quoted us a pretty large sum of money for just the part itself. Not sure where it's located as it does seem more complicated than the normal repairs I have done. We opted to get bench service as it was just a bit more than the part itself.

I forget but Agilent quoted us a pretty large sum of money for just the part itself. Not sure where it's located as it does seem more complicated than the normal repairs I have done. We opted to get bench service as it was just a bit more than the part itself.

Sounds like a drag.... I am going to order a new lamp, put it in, and see if that solves the problem. We might opt to swap the VWD for a DAD from a sales rep for some moolah. Otherwise I will be back to bug you guys again! Thanks all! (for now)

Clement

I seem to have a similar problem. The lamp start, flash briefly (1 second - 1 minutes, depending on the lamp) then shut off and it does the error. The lamp is still cold. I was wondering if the ballast problem is common on older VWD/DAD? Has anyone been able to repair it?

Ballast seems to be a common issue. We are experiencing it on 2/3 Agilent systems. 1100 and a 1200 series. 1200 series was sent in for bench service and it seems okay now. 1100 . . . I just don't shut off the lamp.

Hmmm, so we need to change the ballast. Or by trying multiple time the lamp will eventually turn on? Is there a way to verify this using a multimeter?

First guess is that it is time to replace the lamp. Normal lifetime is 1,000-2,000 hours. How many hours on this lamp?

hi
can you help me please to replace mine once instaler how do I change the lifetime of the lamp and make it zero .

None of these replies address the issue of a "run" starting when the lamp ignition fails... What's going on there?

Theres usually a check box in the method editor for "lamp on required for acquistition". But that would have no effect on the lamp lighting or not lighting.