Are there firewall or port restrictions? Ports 5555 and 5544 should be open for Management Central use and must not be restricted.
Also, At V5R1, another connectivity issue is the PTF/fix levels on the PC and/or iSeries server. With a cumulative level of C1302 or higher (i.e., DSPPTF 5722999/ TL01302 or 5722SS1/TC01302), the Client Access service pack level must be service pack 2, SI01907 or higher.
Is it an authority problem? The user trying to start Management Central may lack the authority to start all of the jobs needed. Check the QYPSJSVR job log (WRKJOB QYPSJSVR) for authority errors. For example, in the joblog, the user may find that QYPSJSVR wasn?t authorized to a particular library in the user?s library list. The fix is to give QYPSJSVR authority to the necessary objects or have QSECOFR issue the startup command.
It?s possible the host information doesn?t reflect a fully qualified name, which is comprised of the host and domain name from the Change TCP/IP Domain (CFGTCP option 12) screen. For example, if the host name is ?HOST? and the domain name is ?DOMAIN.COM,? the fully qualified name is ?HOST.DOMAIN.COM.? This must be assigned to the system IP address in the local host table (CFGTCP option 10) or the domain name server (DNS).