Mass Effect - After the conversation, go to the console. A cut scene will begin and Joker will contact Shepard. After the conversation will be a cut scene of a party member checking if Saren is alive. After another bullet to the head Saren will change into a Geth Sapper like enemy. So this battle will be a bit tough. Just shoot him as he jumps around. When he reaches half his life a cut scene will begin. After the cut scene Saren's shields should be near max again. Just continue shooting him.