I bought a used "good" power supply board this year in Allentown from Mayfair for my BK. I was having display issues, but after I installed the board, I had no displays at all!
As soon as I contacted them they totally refunded my money, AND did all the repairs to my original board. Nobody company is perfect, but I must say they took care of me right away to make it right, and that means a hell of a lot to me in this hobby.