I use a 963 and have had for over a year. I use it with my Jupiter and Omni VI+. I ragchew on SSB and CW, and have never heard the fan come on, much less think its noisy. I know its working cuz Ive seen it on, but its super quiet. So there's another reason to suspect your 963 has a faulty something or other. Hows that for technical savvy?