Had any of the Samaritan believers received the Holy Spirit when Peter and John arrived?
No. At the time Peter and John arrived, the Holy Spirit had fallen on none of the Samaritan believers. They had only been baptized in the name of the Lord Jesus. After Peter and John prayed and laid hands on them, they then received the Holy Spirit.
Les explains that when the apostles at Jerusalem heard Samaria had received the Word of God, they sent Peter and John down. Peter and John prayed for the Samaritan believers that they might receive the Holy Spirit, because as yet He had fallen on none of them; they had only been baptized in the name of the Lord Jesus. Les notes God had His reasons for this. Then Peter and John laid their hands on them, and they received the Holy Spirit. In the surrounding account, Simon was not a true believer but a counterfeit.
(For as yet he was fallen upon none of them: only they were baptized in the name of the Lord Jesus.)
More Questions
Had the Holy Spirit fallen on the Samaritans after they were baptized?
Even though the Samaritans had been baptized in the name of the Lord Jesus, the Holy Spirit had not yet fallen on any of them.
Why weren't the Samaritans given the Holy Spirit right away?
God had his own reasons for not giving the Holy Spirit to the Samaritan believers immediately.