I have a S4 B1 and S4 B2. The S4 B1 is working great but the new B2 that i got in a couple weeks ago worked great for the first few days now I cant get it to hash more than a couple hours. The box would stop hashing but it would stay on, the fans on with a blank (but lit) LCD screen.
I think it is the power supply, i think the load is too much and one time i heard a click when it stopped hashing. I have another S4 but it uses the PCI-E power supply where this new S4 does not, so i can't test that.
It hashes fine with just 3 blades hashing, so that is what I have running now for the past few days so I can get some value out of this S4. I hope that BITMAIN helps me on this one. I have not had any major issues with my other S4 or my S3's. I really do like BITMAIN products...
Same things happen to me. blades temperature was only 53 degrees but I think PSU was getting hotter due to not getting ventilation. Once I re-position the miner, it start to work again. It seemed to happen when ambient temperature gets warm. Also, I set the frequency back to default 200 unless when I'm home to keep an eye out since it stop hashing after few hours while fan is still running at any other setting. It was annoying to see miner stop mining while at work and couldn't hard reboot until I got home. Anyhow, my new method has been working and hope it continued to work. Once weather starts warming up, I won't be able to run my miners due to heat.