For your case, 一定要试一试的话,you need to call high and sell high. 可以试一试从 buy side VP or SVP 开始,看能不能 sell to IB 你以前的关系,that you could bring some fine deals with you。Just forget about starting from Associate level, even 3rd-yr associate will not worth it.
Still,放着 CEO不当,去IB 重新开始,不 make sense。不如学学国内的一些internet CEO们,上市圈到钱兑现后,去VC,PE 以过来人身份 evaluate HI-tech、TMT的 deals。