KRA-405B units S/N 3894 and below do not have Mod 9 incorporated during original manufacturing. Mod 9 or Service Bulletin 9 from Honeywell addresses the need to replace the RF board in case of a board failure. Several components on the original RF board are now obsolete. Therefore, a new RF board has been issued for the KRA-405B. List price for the new RF board is $10168. Unfortunately, the KRA-405B logic/power supply board is not compatible with the new RF board and must be replaced also. List price for the new logic/power supply board is $4623. Lastly, the logic/PS board software set must be replaced.

Total Parts cost (List Price) for the incorporation of KRA-405B Service Bulletin is $14791. Thus, this Service Bulletin is not economically feasible to perform.