Cannot access EMS - Any way to repair/reinstall Exchange?

Hi all

We were experiencing delays in delivery to our Exchange 2013 (CU6) server so I looked in Services and I started an Exchange 2013 service that wasn't running. I can't remember the exact name of that service.

OWA worked as normal BUT active sync on iPhones etc stopped working. It appears there is some problem with the SSL cert (which expires next year) and any HTTPS connection fails.

So I restarted a hub transport service and low and behold OWA stopped working.

I can access OWA if I disable SSL in ISS but cannot login as it keeps redirecting to HTTPS, even though IIS has no HTTP Redirects set up.

When I go to open the https://mail.domain.com/owa in Firefox I get this error: "The Connection was Reset". HTTP does work.

When I open EMS, I get this error:

VERBOSE: Connecting to SERVER.domain.local.
New-PSSession : [server.domain.local] Processing data from remote server SERVER.domain.local failed with the following
error message: The WinRM Shell client cannot process the request. The shell handle passed to the WSMan Shell function
is not valid. The shell handle is valid only when WSManCreateShell function completes successfully. Change the request
including a valid shell handle and try again. For more information, see the about_Remote_Troubleshooting Help topic.
At line:1 char:1+ New-PSSession -ConnectionURI "$connectionUri" -ConfigurationName Microsoft.Excha ...+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+ CategoryInfo          : OpenError: (System.Manageme....RemoteRunspace:RemoteRunspace) [New-PSSession], PSRemotin
   gTransportException+ FullyQualifiedErrorId : -2144108212,PSSessionOpenFailed
Failed to connect to an Exchange server in the current site.
Enter the server FQDN where you want to connect.:

Now I checked IIS and all HTTPS connections (Default Web Site and Exchange Back End) have a cert bonded to them. There was no problem with HTTPS before.

I tried restarting the entire server numerous times, which didn't make a difference.

It's not an authentication issue as I tried logging in as another Administrator which made no difference.

The server is a DC also, I know this isn't recommended but there's only a handful of users.

I have a FULL server backup from a week ago but obviously this is not ideal.

Any ideas how to get this going again? I've been trying to get it going for hours and getting really frustrated now.

Is there any way to uninstall Exchange 2013, re-install it again and import the emails all back again without too much work?

Thanks in advance!