Everything works great, except 1 thing. Now, when I turn on my system, my fans run at full blast at all times. I opened the case to see what exactly was making the noise. It turns out that it is one of the case fans. Based on the Xps420 motherboard diagram, its the one located between 17 and 18. (I don't know if that helps anyone here).
Does anyone have an idea why the fan is going crazy? Could the increase in PSU wattage be to blame? I really don't know for sure, just guessing.
did your new psu come with software disc ??? You may be able to control fan speed with that software if possible. If not you may have to enter bios and see if there are any settings in the to control different fans. CPU CASE ETC
Thanks for your quick reply squirrel64. My PSU did not come with any software to control fan speed. I even tried programs like Speedfan to control them and it dosen't even recognize fans in the system.
I also looked at every area of my BIOS and there are no fan control options either.
can you go into bios and reset the chassis intrusion? I have a precision system and if you boot it w\ the door off, it runs the fan @100% and it's like a jet engine... have to reboot and close case to get it to go to normal.
Thanks guys for all of your help with this. I do have my case door on now, but fan noise persists. itadakimasu, I can't seem to find the feature in my BIOS to reset a chassis intrusion. Could this feature be disabled on my XPS 420? Out of curiosity, where is it on your system?
A higher wattage psu shouldn't cause the fan to run faster, but there are documented cases where it has.
A few options;
Unplug and reseat the fan connector, it may have gotten knocked when you installed the new gpu.
Return the psu and try again with another model, you don't need anywhere near 750 watts, a 500-550 would be more than sufficient.
I've had no problems with Corsair or Antec when used as a replacement for Dell power supplies.
Folks... Just went through the same exact scenario as above. Replaced my 325w in my XPS 420 because it's fan started making noise (the PSU fan). Plugged in a brand new OCZ Silencer Mk II 750W. The main CPU fan would do just as stated above... it would always run wide open. Tried Speedfan but since the Dell fan is special speedfan would not recognize it. Fought with the darn thing for close to two weeks. Even changed out the thermal compound with some Arctic Silver. Finally surrendered and bought a new fan for the old PSU. Replaced the PSU fan, plugged in the old PSU and everything is back to normal now. It doesn't make sense... but all I know is that Dell can be a little funny about non-dell parts. I guess I could have bought a new CPU fan and stuck with the new PSU… but then again I’m not a gamer and 325W has served me well so far.