Chromatography Forum

New to forums and have a maintenance issue with a HP 6890 PID connected to a OIC Lamp Power Supply 4430. The lamp went out suddenly during the day, but not during a run. It has been working in the morning and shut off, in the afternoon I went to start it up again and the lamp on doesn't stay lit, it goes out immediately. The lamp used to take several times to get it to stay lit, but it would eventually come on. Is it common for a PID lamp to go out so sudden? The fuse is good and wire was tested with another one. Any suggestions besides change a part?

Thanks, Michael

Friday afternoon and still no replies? I'll venture a possible explanation even though I have never personally operated a PID detector. If I am correct in assuming that the lamp in the PID is a deuterium lamp, the symptoms you observed fit the scenario of an aged and failing HPLC lamp. Check the hours of use of your lamp if known and the expected lifetime of the lamp. If I am totally of course, perhaps someone else will suggest a more reasonable explanation.

It is not a deuterium lamp, but the same general rules apply. The lifetime is limited, and in most cases a lamp lasts for a year or two. If the lamp won't stay lit either the lamp or the power supply is bad. I'd start with the cheaper option, get a new lamp and see if that solves the problem.

Michaelquerty,

If you changed out the HV cable, that means you have another power supply. Change that out as well. Also, if I am not mistaken, the 4430 has a lamp saver feature on the back so make sure that is off while you are troubleshooting the detector. Finally, lamps do have a finite shelf life so if the one you have in there has been around for a while, it is possible that it has died even if just installed.

Best regards.

The lamp saver is not activated unless there is a start cable connected to the controller from the GC. I doubt if that is the problem, the fact that it would take several tries to light the lamp is a sign of a failing lamp. I wouldn't call the failure sudden, there was a warning sign that the lamp was reaching the end of its useful life.

I have had this happen before. We run several GC's with the OI tandem FID/PID detector. Sometimes it's the bulb, but sometimes it's the power supply. I actually have a power supply on order from them now because we have a dead one.

Not trying to hijack this thread but along the same topic, does anyone know where it might be possible to get the power supply checked out and repaired? I have a couple of bad ones and I would imagine some repairs would be a lot cheaper than buying brand new ones.

Omaejel,

I will ask someone I know if they repair the OI supply. On a different note, are you interested in testing a beta unit power supply? Where are you located?

Best regards.

AICMM,

I would love to find out that we could get those OI lamp power supplies repairs.

We are always interested in trying out new products here at our lab. If you would like to contact me about setting something up I can be reached at JBrown@esclabsciences.com. We are located just outside of Nashville, TN.