Yes that is an old issue. i actually was the first to report this issue with my miner.. The orginal thread on hashtalk is gone along with JG. thats another story lol. Anyway.. here is the official statement from bitmain at the time.
Dear customers,
We are sorry to inform you that we do find a critical defect of power supply in the first batch and the first part of batch 2 Antminer S4 shipment, and have issued an official announcement on bitcointalk community regarding power supply replacement for these miners. Please find details in the following link,
https://bitcointalk.org/index.php?topic=796839.msg9207574#msg9207574We assume you might have not came across the failure issues like other customers do as we have not yet received any info from you on the power supply problems. But we do suggest you nip it in the bud and keep an eye on your miners which seems to be running well.
we decide to send you new replacement PSUs, which have been optized and improved from the previous ones and will avoid similar issues as stated in the above-mentioned link.
Now please provide us with the Order Confirmation page from Bitmaintech.com of your B1 or first part of B2 S4 miners and confirm with us your full address, to which we will ship out new replacement PSUs.
Please accept our sincere apology for the inconvenience.
Tim Shao
http://btcfordummies.ca/bitmain-s4-have-a-fire-extinguisher-near-by/OCTOBER 5, 2014
Best Regards
d57heinz