For anyone to be able to assist, need some additional info:
What version of the TSM Client and OS are we running?
What version of the TSM Server and OS, that the TSM Client is backing up to?
Are we able to perform a manual backup?
In the dsmerror.log/dsmsched.log were there any message around the time frame when the schedule backup failed?
If we start the schedule daemon/service in the foreground, do we see schedule information or do we see an error message?
Is the schedule daemon/service running at the time?