Frigidaire dryer getting E-61 error code replaced main control board.

E61 is a stuck or failed heated relay on the main board. Since you already put a board in it I would check the heater ohm. I believe you have a grounded heater to unit case. I have seen this happen before two different times. 95% chance the heater grounded is your issue. Let us know the outcome. Here is a video link for the E61 error https://www.youtube.com/watch?v=p0BFUtJzV9s