“Since ye believed” or “When ye believed” in Acts 19:2?

The phrase “since ye believed” is one aorist verb, which indicates the “belief” as occurring in the past. “Since” is correct because Paul is asking if there was a reception of the Holy Ghost following the belief. These disciples had not received the Holy Spirit until Paul’s laying of hands (Acts 19:6), so there is no doctrine of second reception [of the Holy Spirit] promoted by this rendering.