Antminer B7

[Dohzer43]

Hello all, really lacking for information regarding this miner in my searches. I've removed the rear ventilation plate and fabricated a second fan bracket for the rear and have a Noctua industrial 3000 rpm running at full steam exhausting. I have this thing running pretty cool. I've attempted to increase the frequency via advancedminer.cgi from 500 to 525 but the miner dashboard does not physically show a visual change from 500. Was wandering what the deal is.... Hashrate has not seemed to improve. It actually seems worse..... Thoughts/experiences with this? Appreciate any responses or PM's