Solved! [SOLVED] Help identifying laptop fan terminal

Growtopia Jaw

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I have a Dell Latitude E6220 and the laptop fan has 4 pins. The wires aren't colored and are all black. I'm not sure which terminal is which and for some reason, there are 2 wires soldered to one terminal.

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The model number of the fan is Forcecon DFS400805L10T
 
Solution
theres two possibilities

the first one,since i see the pics showing the first pinout on the fan doesnt soldered,the 2nd pinout was the VCC (5V) and the 3rd was data/sync (temp,etc) and the 4th are the GND,the 3rd seems the Data/sync and that shows 1V+,but i think it do share the data/sync ground pinout with gnd pinout like the common laptop fan pinout

the second one,since theres one pinout left,there seems possibility of VCC,Data+,Data-,GND pinout.

but as long the motherboard gain temperature data from sync/data pinout from the fan itself,it should be fine,thats why you can turn the laptop into fanless by bypassing the data/sync (cut the fan main power cable) without the VCC for fan itself.

many laptops fan came with only 3...

YehezkielLee

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seems you should connect the pinout before and check the voltage with multimeter i think ,but i bet the 4th pinout was VCC and 1st pinout was GND,maybe its a Data+/- or sync
 

Growtopia Jaw

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Jun 8, 2021
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I took some measurements of the fan voltage (directly from the connector) and here are the results

Pin 1 (+), Pin 2 (-): 3.6V
Pin 1 (+), Pin 3 (-): 1.8V
Pin 1 (+), Pin 4 (-): 3.6V

gH2Mpew.jpg


From the image below:
7Z3vAjL.jpg


The first pin on the left side is blank and there are 2 wires (3 and 4) connected to the 3rd pin from the left.

The 2nd pin from the left is (2) and the pin on the rightmost side is (1)

There are some letters on top of the fan pins and I'm not sure if those will be of any help.

The first letter starting from the pin on the left is (P), 2nd (F), 3rd (G) and 4th (U)

Please ask if this is confusing
 
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YehezkielLee

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theres two possibilities

the first one,since i see the pics showing the first pinout on the fan doesnt soldered,the 2nd pinout was the VCC (5V) and the 3rd was data/sync (temp,etc) and the 4th are the GND,the 3rd seems the Data/sync and that shows 1V+,but i think it do share the data/sync ground pinout with gnd pinout like the common laptop fan pinout

the second one,since theres one pinout left,there seems possibility of VCC,Data+,Data-,GND pinout.

but as long the motherboard gain temperature data from sync/data pinout from the fan itself,it should be fine,thats why you can turn the laptop into fanless by bypassing the data/sync (cut the fan main power cable) without the VCC for fan itself.

many laptops fan came with only 3 pinout,but as long they can share same ground between the data and vcc,3 or 4 pin seems like work like the same.


hope it helps...
have a nice day :)

edit : after i seen first pics,seems like u need to just swap it to abc/cba
just test it,as long the VCC and GND doesnt get inversed,thats should be fine,always use the multimeter to test the GND and VCC on both of pinout,anyway whats the problem of the fan tho?,doesnt it get spin or it do get unexpected-turnoff,or wrong fan temp and speed info?
 
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Solution

Growtopia Jaw

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I’m deciding whether or not to cut the data sync wires as an external fan isn’t enough to bring down the laptop’s temperature. This laptop frequently overheats and thermal paste such as Cooler Master doesn’t help either. I’ve cleaned the fan and temperature is still as high as 90-100 degree celcius. Laptop shuts down any time it wants to.
 
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YehezkielLee

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yeah,seems like the fan doesn't spin up propely,in case maybe you need to change the fan itself,actually u can change with the different model for alternative,with using pinout soldering method,but trying to resoldering have little change to fix it,

does the temperature getting like burning hot when you touch the surface?
if its not that burning hot,then the the sensor may send misinfomed temperature data like usual problem of laptop fan

sometime if you cut the data/sync cable maybe the laptop itself wont booting up more than 10-30 second cuz temperature check failure,but sometime laptop won't mind if theres no temperature info or fan checking failure,or whatever,if this occur,just connect the pinout back,but lets give a try if u wanna to...
 
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Growtopia Jaw

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Ok so i tested the fan and here is the result
I cut the wire one by one to see if the fan spins or not

cut Wire 1: No fan spin
cut Wire 2: Fan spin
cut Wire 3: Fan spin
cut Wire 4: No fan spin

cut Wire 2 and cut Wire 3: Fan spin

So I think I can confirm wire (1) is VCC and wire (4) is Ground. Wire (2) and (3) might be data / sync pins

Also, I think I busted my fan. Even when the temperature reaches 100 degree, the fan won’t spin faster. It is stuck in its lowest speed.
 
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Growtopia Jaw

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Since the fan itself is 5V 0.45A and the fan is only drawing 3.3V, I took 5V line from one of the SATA power pins and soldered it directly to Pin 1 (+) and Pin 4 (-). The fan now runs at full speed, exactly what I wanted and the CPU temp is 40-50 degree celcius during idle, which is quite impressive considering it is idling around 70 degree celcius before.

Honestly, this is the hackiest thing I've ever done.

jcMWCat.jpg
 
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YehezkielLee

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have you testing to control the fan with speedfan? or even have you check the bios/uefi for fan speed?

cz sometime if you directly connecting the fan to 5v it do reducing the fan lifespan itself?
 

Growtopia Jaw

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Jun 8, 2021
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have you testing to control the fan with speedfan? or even have you check the bios/uefi for fan speed?

cz sometime if you directly connecting the fan to 5v it do reducing the fan lifespan itself?

Sorry for the really slow reply. I have not tested SpeedFan on Windows since it is pointless that I don’t use Windows most of the time. I mainly use Linux and I have tried different methods of controlling the fan speed in Linux and it never works. I occasionally use macOS for productivity related workload on this laptop. I use different OS for different workload so even if SpeedFan works on Windows, the fan speed couldn’t be controlled in macOS and Linux.

The Dell BIOS really sucks. There is no option to change the fan speed settings.

I honestly do not care if I reduce the lifespan of the fan since this laptop is more than 10 years old. I’m currently using this laptop in the best way I could and maybe I will have a chance to use a new computer in the future. That doesn’t seem very likely especially in this Covid situation.