I would try the following guides from zendesk:

https://bitmain.zendesk.com/hc/en-us/articles/204875015-How-to-diagnose-S5-hashing-PCB

Then

https://bitmain.zendesk.com/hc/en-us/articles/203559969-My-S5-hashes-at-about-600GH-S

Can you post a status picture is it seeing both hashing modules on S5?  And what PSU are you using (model and watts)?