Chromatography Forum

What does the flashing red check mark on the UV detector indicate? Would it be the monochrometer, power supply going bad, or other problem? I changed the Deuterium lamp and solvent to HPLC grade water. The check mark stills flashes red.

Update: “A/Z/ OUT OF RANGE” error is displayed, but THF and HPLC grade water result in the same error.

Any advice will be greatly appreciated.

Please change the solvent again! I think it's still not quantitative enough to evaluate. Download granny 2.0

Thank you for your advice. Changing the solvent again was a very good idea. Unfortunately it did not work, even after changing the D2 lamp.

I ended up lubricating the worm drive and thoroughly cleaning the monochrometer interior, flow cell parts, and fan area.

One or all of these cured the problem. The UV detector can now autozero using the original solvent bottle. . . for now.