Hi,
Thank you for posting in Symantec community.
I would be glad to answer your query.
When you attempted to repair the SEPM what was the error message? Can you try to repair the SEPM with the help of downloaded setup files?
If not helped then need to check scm-server-0.log and catalina.out file.
In worst case if you had to uninstall SEPM but will not have to uninstall SEP clients from end user machines. You can simply restore the client-server communication replacing Sylink.xml.
Total how many clients are there in the network?
How many database backup's you have?