You simply pick up the second laryngoscope, which you always prepare and check before proceeding to an RSI, and carry on. No problem. If you haven't prepared a second laryngoscope then you will do in future.

It is essential, when planning to perform an RSI, to prepare for the worst: to have two working laryngoscopes, to have at least two endotracheal tubes prepared, to have intubating aids such as bougies, Magill forceps, suction, bag-valve-mask, all ready. You may also want to have a McCoy laryngoscope, LMA, lighted stylet ready also.