The first step is to contact Technical Support.  They will ask for the Test Function Block Device ID. 

Device IDs ending with "0004" through "0070" as the last four digits were built on an older hardware platform.  Never write to the  RESTART parameter in the Resource Block, this will cause the TFB to become unstable. We may be able to repair these TFBs under a Return Material Authorization.  You must have pre-approval from a FieldComm Group staff member to initiate an RMA. 

If the Test Function Block cannot be repaired, a replacement can be purchased.