Fixing auto threader on Baby Lock Enlighten Overlocker?

Baby Lock Enlighten Overlocker Model: BLE3ATW-2
How can I fix the automatic needle threader on my Baby Lock Enlighten overlocker? The guides seem to be placed correctly either side of the needle (same is true on left and right needles) but the thread is just not drawn through the needle. There's supposed to be a hook on the guides, which passes through the eye of the needle but I cannot see one. Any ideas?