I encountered a problem with our 600 MHz NMR instrument. When acquiring the line shape sample, while spinning, the chloroform peak is split into 9 lines, each one 20 Hz apart (speed at which the sample is spun). Without spinning, the peak is very, very broad. I contacted our service engineer and it seems that there is a dropped cryoshim on the magnet. What exactly does that mean? How could it have happened and can it be corrected? The service engineer will help my tomorrow, but I am just curious in the mean time of what could have gone wrong? Thank you.