I followed Dogie's setup guide here: https://bitcointalksearch.org/topic/guide-dogies-comprehensive-bitmain-antminer-s3-setup-hd-702653
The 1st S3 miner works perfectly at around 440Ghs.
The 2nd S3 initially only started with 1 chain visible with a hash rate of 200Ghs.
I tried a few different CX750 power supplies but same result. Now the S3 starts but does not hash at all, a bleep and it restarts
For the time it is running I can still only see chain 1 visible but showing 0.0Ghs
Emailed and posted here, hoping Bitmain will resolve the issue.
You might want to remove the covers and see if the cables are all seated properly. Also check to make sure your pools are all filled in and "alive."