I cannot help you, we do not have this instrument in the LAB. I will ask around

Problems with the initial calibration process could be related with the lamps. Do the UV and the halogen lamps works well? Check both are on. Check also the life of the UV lamp, maybe you should change it because is out of lifetime. 

Thanks for the answers. The spectrophotometer is new and the problem is not on the lamps but probably on the Pre-monochromator. This may be some factory problem for this series.

So what I would like to know is if anyone have experienced this kind of problem?

In uv lambda 25 perkinelmer we face monochromator gratting motor problem it does not adjust on zero slit and sounds.