Ballast question

I have a 1Kw Cali Ballast that has both an intake and exhaust fan on it. It sounds like the intake might be dying.. Medium buzzing coming from right next to it. In the past I have had 600w ballasts that only have an exhaust.. As with most electronics this is the most important.. Does this mean that I'll be fine with one fan still working if the intake does indeed fail, or can a 1Kw ballast not cool properly witbout both fans?
Thanks in advance

It will die when it die's...It'll run till then..
Mine only have single fans...The exhaust will do good enough.....Better then it attempting to "push" air through it.