Q: Yosemite + server 4 - completely reset OD

I'm running Server 4.1 on OS X Yosemite 10.10.3 and there's a problem with Open Directory.  When I run a fullstatus command I get an error

I've tried using slapconfig to destroy the ldap server but that retains whatever is wrong with the settings so a new master gives the same result.  I've tried re-initialising Server.app but that, too, retains the settings.  What I need is a way to completely reset Open Directory and the ldap server without having to wipe and re-install OS X.  Can anyone help?