FLD Xenon Lamp Change Error Message: Lamp cover is open

May I ask? Did you take an official FLD training? Working on the innards of an FLD usually is for trained staff only. Many things can go wrong here, e.g. replacing the lamp is much different to replacing the lamp on a UV detector. One can screw up the alignment and create a massive loss in intensity.

This is a safety feature. It prevents the Xe lamp from being ignited, if the metal cover (=lamp house) is not in place. Either the five bolts are not tightened enough (but don't "gorilla" them in) or the FLF (frontend board), which sits underneath the optical unit, is faulty. The FLF has a safety switch, which detects the presence of the lamp house (there's a black plastic rod facing upwards from the FLF towards the lamp housing.

Please keep in mind: Tweaking the safety switch e.g. with tape or a screwdriver is dangerous and must not been done. If tweaked, you have live 600V directly in front of you, plus the lamp can be ignited and cause damage to your eyes.

Unfortunately, no. We are quite pushed for time on a current project and understand the risks associated with a DIY job - desperate times!

Thank you for your input, I'll keep this in mind. Hopefully it is just because it's not tight enough as the FLF was fine before this (yesterday morning).

A rejig of the lamp house and retightening of the bolts seemed to do the trick, ensuring the safety switch was down when the lamp housing replaced as informed above. Thanks sschombu :)

You're welcome. Glad it's working now. Keep in mind that after any change to the optics path, a wavelength calibration is required.