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March 22nd, 2023 16:00
Latitude E6410 CPU fan wiring
Hello everyone!
Just got my hands on a very nice E6410. Fresh install and grabbing drivers for it - it's my first Latitude laptop, and I must say, very sleek! Not quite the Latitude I wanted but still, very cool.
Now, one annoyance I've found with the laptop, is a lack of ability to be able to control the CPU fan - it seems to have a mind of it's own, and it ramps up/down whenever it wants. Typically with the way I use computers, I like to be able to have control over this, you know, to keep temperatures down, and help with performance.
Previously what I've done with computers where the BIOS doesn't provide any fan control options, is physically disconnect fan pins which are responsible for regulating the speed, and make the fans default to max speed constantly, it might be overkill for some people, but I am totally fine with it - I have plently of background noise where I am anyway, so something like a fan is hardly a disturbance (especially considering how I am pretty much always wearing headphones anyway...).
I actually took some pictures of the inside, but can't see a way to attach photos here, essentially the fan connector has black, yellow, red, blue cables. Here's some pics of an identical one I found on the internet:
https://www.ebay.com/itm/304804354901
Would anyone happen to know which colours might be the ones I need to disconnect? I am removing the pins from the connector "non-destructively" which is rather tedious, so far I have only tried with the blue pin removed, and it seems that this stopped the fan completely, so clearly that's an important one. Don't really want to try them all manually, so thought I would ask here first.
Many thanks in advance!
ejn63
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March 22nd, 2023 18:00
The fan is operated by a circuit containing a thermistor - it spins up when a temperature setpoint is reached.
That's the wire you disconnected -- without it, the fan won't spin at all.
The only way you will achieve what you want to is to wire the fan to a USB port outside the case -- that will give you a constant-on fan. There is nowhere you can wire the fan internally to do that.
AVaughn
4 Posts
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March 23rd, 2023 04:00
Hi ejn63,
Thanks for the reply. Just to check, how sure are you about what you wrote? If you're quite certain, then I am more than happy to take your word for it.
It leads me onto a second question - this is more so just my curiosity, and also wanting to learn more about the laptop: what do the other pins do, for example: are black and red performing standard functions, and if so, what does yellow do?
I ran speedfan and speccy on the PC, both of these programs were able to grab a temperature reading from 1) the CPU, and 2) the HDD - i think they "tap into" the hardware for their readings - out of curiosity, would you happen to know if the temperature provided by something like speccy/speedfan is going to be analogous (the same) as the temperature that the "thermistor circuit" is picking up?
This is just more so that I can understand the numbers the computer is seeing and using to control the fan - because if what I can see inside the OS with 3rd party programs is very accurate to what the mobo circuit is using, that is a good thing.
Let me know if I sound crazy: we don't think there'd be a way to trick the thermistor circuit into reporting a false (high) reading, to get the fans going? This is obviously not a modification that sane people would want to make. I don't have the laptop in front of me to be able to take a look at how "feasible" any of this might be. Just thinking outside the box a bit, I'm not a professional engineer.
With the other option of wiring fan to a USB-port or something, I wouldn't mind losing a USB port to the CPU fan, (granted the fan is 5V and would get full power from such a port) - there might be a way to route some wires "inside the laptop" from the fan to a port (the solution might be "dodgy", but it can't look dodgy from the outside !)
Let me know your thoughts about the above, and whether you think this is a fool's gambit, I like the laptop but the "fan-curve" was clearly set to be "as quiet as possible" which is just not something I can put up with!
AVaughn
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April 11th, 2023 04:00
Hello,
It has been a while but I thought I'd update the topic. Luckily the CPU fan is 5V, 0.5A (exactly the same as the max power supplied by the USB standard, so I wired up the power pins from the CPU fan to one of the USB ports (yes, effectively sacrificing a USB port...), and now the fan runs at full speed all the time, it's a start!
And whoa, that fan can blow! Idle CPU temps in Windows 7 Ultimate are 26-31 degrees (i5-560M), and it's certainly not reaching those 70s like it used to, I think under load it doesn't surpass the 50s.
I have an idea to integrate a discrete slide potentiometer into the circuit, to give some "nice" analogue control over fan speed (I know potentiometers aren't as good as pwm, but I haven't ruled that out either).
Also, if I switch out my CPU to an i7-660LM (an i7 quad core with only a 25W TDP), and swap out the hdd for an ssd, this laptop will probably really fly whilst also being the coolest.
Not great that I had to whip out the soldering iron, but at the very least this type of fan control is very "rigid", as in, no BIOS or OS can ever override it.
Great laptop so far!