Hi to all

I have Bitmain S3 have been mining last few months no problems. Couple days ago I power up the miner and both fans run flat out but no mining. I thought perhaps it is software issue so I tried a factory reset using a paperclip near the ethernet port and once rebooted found the miner on my network and re-installed the configuration .gz file that I saved months ago. This made no difference still when I power up the S3 the fans run flat out but no mining. I have also changed the psu I have a 32A, a 40A and an ATX Corsair CX600 which puts out 46A on the 12V rail. Swapping between these supplies also makes no difference the S3 fans just continue to run flat out with no mining.
Not sure what to try next any help much appreciated