One of my online gaming buddies just upgraded his rig... new power supply (Corsair 650 TX) and a new video card (ATI 5770) Everything works likes it's supposed to, but since upgrading his case fans run at full volume the moment the PC is powered on and do not revert to a normal level. The case is an Antec 900 and they're (possibly) the original fans. Keeping in mind I can't just walk across the street to see this for myself, I'm asking for some help here. As best I can tell, the fans utilize molex connectors. It's my suspicion that the new PSU has something to do with the loud fans... although I've never heard of this before. I know it's a long shot, but I'm hoping someone has seen something similar.
Does he have his case fans plugged into the motherboard?
If his case fans are plugged directly into the PSU molex connectors, then he just needs to turn each fan speed control on the Antec 900 case from high to either medium or low. On the Antec 900 case the speed controlls can be a little difficult to find, but if he looks for them or looks in the users manual, he will find them.
It was my understanding that they are NOT plugged into the motherboard... so presumably that means they're molex connectors. I've emailed him a copy of the user's manual with some directions... so hopefully that'll solve that. I just didn't think that switching PSUs would bring about a change in fan RPMs. That's new to me.
This is a Team Fortress 2 gaming buddy and I know the extra noise was really bothering him yesterday (day 1 with his new PSU/video card) The card and the PSU are both high quality / lowish noise parts... and he swear that it's his case fans that are turned up now... and the parts he added are lower heat than the parts that came out... so logically it's not a thermal issue. I'll hopefully have something to post tonight. He's the reason I have admin rights on the server I play on... I figured it was the least I could do to try to help him.
The Molex connectors on all power supplies are standardized, and all put out the same voltage. His fan speed problem is not related to the power supply, if this is how he has things connected.
12v +/- 5%, the full range there is 1.2 volts
If the old psu was outputting low voltage ( let's say 11.7 ) and and the new psu is outputting higher voltage ( let's say 12.2 ) then the fans that are connected to it are receiving an extra half a volt, which can lead to them running several hundred RPM's faster.