The following process will help you reset the vRealize Operations Manager 7 root password. If you have locked the account out attempting to use what you thought was the password the steps below will also work as the account is unlocked after a reboot.
Open a console session from your vSphere Web Client to the vRealize Operations Manager.
Then restart the vROPS Appliance.
When you see the boot loader screen add the following to the end of the string init=/bin/bash
Press enter and wait while the appliance boots into the shell
Type passwd and press enter to input the new password twice for the root user.
Type in reboot and press enter to restart the appliance.
Once the VM has rebooted press Alt + F1 to switch to the shell.
Now you should be able to login as the root user with the password you just configured.