Studio 15 fan running at maximum RPM "randomly"

Hello everyone,

I think I may have some interesting information for those who own the Studio 15 and have been unlucky enough to experience the spontaneous loud fan that occasionally turns on. By "occasionally" I mean almost all the time and by "loud" I mean full blast for hours on end. This problem may persist whether the machine is running the A02, 03, or 05 BIOS and can be extremely frustrating, especially in a quiet environment such as a library or lecture hall. It doesn't appear to be a software issue or a BIOS issue since the problem persists with any version. It is in now way related to dust or high temperatures.

I recently noticed that applying pressure in the area of interest (circled in red) seems to activate the fan into running at maximum RPM; at the same time you may observe that taking pressure off the area of interest makes the fan stop immediately (or soon after, presumably because the plastics bend back into shape). I am not sure whether this problem is the result of the motherboard (which observably flexes) or that pictured screw or whether something is making contact underneath the keyboard, but I thought I'd share this bit of information with others who may be as frustrated as I am with this problem. I will be dismantling the entire computer soon to look closer into the issue.

EDIT: it also appears that gently bending the laptop mainboard upwards (when the laptop is sitting normally on a desk, not upside down) stops the fan immediately.

Bog

 

I think your on to something here. I noticed that the bottom of mine is slightly bent as well.

 

Update, i tried what you said on mine and it had no affect. I even put enough pressure to bend the board while it was working and it was still on. What i did notice though is that the heatsink that is directly connected to the fan without a copper heat pipe, im thinking its the gpu but im not sure, was running hot and i think that is what is setting it off. the heat pipe was cool.

 

Bog,
the problem is not the motherboard, sounds like a failed fan controller. The fan controller is basically a small chip which allows either no current to pass through it, 2.5 volts to pass through it or 5v to pass through it.
It seems like the 2.5V rail burned out probably from a short or a possibly defective chip. Thus you are only getting 0 fan speed or 100% fan speed.

You can replace the physical fan controller chip if you want to yourself. If you can get a high res picture I can show you exactly what chip you need to replace, and which one to replace it with.

If you have a warranty you can get the system serviced. You can tell them that the fan controller on the motherboard is not working properly and they will give you a new motherboard.

The occurence with the pressure on the board is not a coincdence. If you put pressure on any of these chips when working properly or not you will add flex to the chip, and will cause certain pathways to become engagedd or disengaged. This is why when you put pressure the fans spin, and when you relieve pressure the fans stop.

If you have a second fan in the system we can bypass this issue by wiring both fans to a working fan controller.
If not you can either replace the fan controller chip yourself or have Dell give you a new motherboard.

K-TRON

 

I had motherboard replacement.
Trust me - It is ISSUE not only for you.
I have the same problem with two motherboards...
It is BIOS ISSUE, like "sound crackling" and "Hard Drive clicking - FirmWare Issue"

 

^ That is interesting info, guys. I think I will just hand over the laptop to Dell for repair. Hopefully this problem isn't widespread among their motherboards.

I will try to get a photo of the controller, K-tron, but it may be difficult to access without dismantling the computer (and unfortunately I am very busy with school work atm). Thanks,

Bog

PS; is there any way to repair the faulty controller rather than replacing the chip or the motherboard altogether? Just hopeful, I'm not too keen at sending my main computer away at a time like this.

 

Hey guys,

I've experienced this before, it's really annoying. So I call up Dell, they replace the heatsink/fan and the problem is gone. I'd suggest you call Dell Support, they have to replace this. I've also had my motherboard and my DVD drive replaced, because the board was acting really weird (DVD eject, long time loading BIOS before booting up OS). The first problem was this random fan behaviour, got it replaced, problem solved.
Any questions, I'd be glad to help.

Rafa

PS: I also did this video for Dell Support, the only thing that helped was lifting the left corner of the laptop and the fan automatically turned down again.
http://www.youtube.com/watch?v=ISIcmEOJt88

 

I had the same problem! I called Dell and they changed the CPU fan and the system board. I hope the problem doesn't come back!

 

I suspect that the faulty controller is caused by the fact that the motherboard flexes so much... the chip is right in the middle of the PCB board where the bending action is most pronounced.

 

Just an update, I took the Dell apart and inspected the area of interest; I couldn't identify the fan controller chip specifically, but I couldn't see any evidence of damage to the board or any of its components. I tried running the computer by removing the speaker/media button assembly and the metal frame (that supports the keyboard and wires underneath) individually to see if the problem went away; no dice. It looks like it is a problem with the controller.

 

Looks like I'm not the only one with issues. As of right now, my fan is running 100%, for 4 hours straight now, heh...I usually fix it by lifting it, but now I guess I'll call Dell during the christmas break to get the motherboard replaced.

 

Got the same issue here, bought Studio 1735 in October, the fan started behaving a little erratically a couple of weeks ago, just flashed the BIOS and now its constant fan running 100%, will be in contact with Dell tomorrow.