(PC Support tip) Database Connection Error: Failed OpenConnection: Login failed for user ‘td’

This happens due to the fact that when adding the DB server into ALM, the connect string for the DB server gets added as a "localhost" as opposed to actual server name which is why the connection fails from PCS. Sometimes it works fine from ALM because ALM and DB could be on same machine. After editing the connection string under Site Admin->DB Servers tab with actual DB hostname, PCS to DB connection should work fine as expected.