S7 Hash rate dropping

[4thefall3n]

Hello,

I have a antminer S7 that isn't hitting the expected speeds of 4.73, not even close. Most of the time its running at 3.5 t/h or it slowly drops down to about 800 g/hs from 3.5. The temps are staying way down I'm not sure what could be cause this loss of hash rate.

https://imgur.com/a/BONdS