Hello and thank you for choosing JA for your support needs. Well you can find the Logic Board on http://www.fastprinters.com/webpn139.asp
They have the replacement part that you would need to support your client. Next, you would do well to replace the second faulty Logic Board also. It would be easier to either have them serviced or replaced the boards with the problems as they will take several days of non-stop trouble shooting or replacement of parts on the Logic Board to resolve this issue Sir or Madam.