Inspiron 5675, PSU fan

Check for dust inside the PC, and especially the power supply air intake. 

Locate the tower where it can get cool air intake.  Sitting on a floor is not very good, even the cleanest locations it can collect dust.  Inside a compartment in a computer desk has also shown to not be very good unless the back and front are completely open. 

Finally it may be a sign the power supply is failing.

(I used to live in KC North).

Did you ever find a solution?  I have a newer 5675 and had been plagued with fan noise that all of the sudden goes full speed for a few seconds (like you said, maybe up to 10 seconds) then back down.  It happens when the computer is idle, or when using it, but I don't game so it's just email, web, etc.

I installed HWInfo to monitor the fans.  When the fan went turbo, the CPU, GPU and case fan speeds were normal and do not change when the fan drops back to normal.  So it's not any of those fans.

What I found was the power supply fan is going crazy every once in a while. It goes full speed for a few seconds then settles down.  It's very loud.  

Looking at the power supply, there is NO visible input venting!  It must be on the bottom, which is mounted against the bottom of the chassis!  How does air flow through the power supply?  There is about 1/4" gap between the power supply and chassis.  No air vents on the sides or top!!!  The power supply feels very hot.  

Does the 5675 power supply really have no outward facing input venting?  This seems like a bad design that will kill the power supply quickly and is probably the reason the fan goes crazy every now and then trying to exhaust all that built-up hot air.

Dell Does not support, validate, or otherwise accept HWINFO for troubleshooting or anything else.

---

@speedstep wrote:

Dell Does not support, validate, or otherwise accept HWINFO for troubleshooting or anything else.

---

What an odd reply.  You DON'T work for Dell, but you SPEAK for Dell?  

Does Dell support me putting my hand behind the power supply exhaust fan and feeling the blast of air coming out the back or touching the power supply casing and feeling it's overly hot?

lancorp,

speedstep is correct. The usage of 3rd party tools is fine for general troubleshooting. But, the 3rd party software of "failure" is not supported. When it comes to actual in warranty hardware replacement, Dell will insist that the "failure" be shown in our Dell ePSA diagnostics and in the Dell SA (SupportAssist) diagnostics. Does this clarify your questions?

Getting back to this because I live with the power supply fan ramping up to full speed about 10 times or more a day.

Forget I ever said anything about HWINFO.  Focus on the fact that I have visually inspected all the fans when it goes "turbo fan mode" and none of the case, GPU or CPU fans are the problem.  The noise does not come from those areas of the case.  It comes from the power supply.

Like I said (which apparently both you skipped over), I put my hand behind the power supply exhaust vent and can feel the turbo blast of air when it happens.  My ears can hear it comes from the power supply.  No 3rd party tools needed (unless my hand and ears are considered a tool).

I have a 5680 (same chassis) that does the same thing.  Same chassis, same poor venting on the power supply with the intake fan turned upside down against the bottom of the case.  Who thought putting the power supply fan upside down against the bottom of the case was a good idea?  The intake fan should point INTO the case, not be up against the chassis where it can't draw in air!

eDiagnostics will not detect an problem because it is very intermittent.  ALWAYS when I log in, and mostly when I start a browser.  Computer is never off.  It's on 24/7.  No heavy activity.  I don't game or create video.  Standard office work.

Ideas?

lancorp,

So you are not saying that the physical fans are defective. You are saying that the BIOS, operating system, and software controlling the fans is amiss? For my notes, send me both of your Inspiron Desktops service tag numbers in a private message.

@lancorp 

Did you ever find resolution? My BRAND NEW dell is doing the same thing. It is not a cpu case fan or other fan. It is the PSU fan. It sounds like it is going to explode into space! Thanks.

I have this problem as well and it only happens in windows 10. When I install linux mint 20 it never spins up. So it's definitely a windows process that is causing this.