You must ensure that the former coordinator process is no longer running before attempting failover.
In a worst case scenario, the former coordinator computer might be running but disconnected from the network, or in a hardware hibernation state. In this situation, you cannot log into the coordinator computer, which would be unreachable by tools such as Sybase Central, but the coordinator computer could start functioning normally without warning. Ideally, the computer on which the coordinator was running should be shut down during the manual failover process.