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6 Posts
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17997
December 7th, 2018 22:00
cpu fan failure optiplex 755
I replace the fan in it and everything's been fine until the past week the fan speeds up and now says the fan failure whenever I boot it up what can I do about this
bradthetechnut
7 Technologist
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9.2K Posts
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December 9th, 2018 21:00
Hi @casper803,
By any chance did you replace the CPU fan with one exactly like it? Dell is very proprietary, fans included.
speedstep
9 Legend
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47K Posts
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December 8th, 2018 11:00
The fan is not standard. The wiring is different. Plugging standard into 755 or the other way round can burn up the fan tach signal on the motherboard.
DELL FAN WIRING IS NOT STANDARD. DELL FAN CONVERSION.
https://www.amazon.com/Pocaton-Female-Socket-Connector-Cooling/dp/B073XJV5L9/
casper803
6 Posts
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December 10th, 2018 20:00
no I did not I used a little bit bigger one that was in an Old Dell XPS is work for 8 or 9 months now but all the sudden started doing this
speedstep
9 Legend
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47K Posts
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December 11th, 2018 04:00
Fans are like cars they have so many hours on them. You did not replace with new fan so that is where the problem lies.
You did not say what size. There is not one size that fits all 755 models.
casper803
6 Posts
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December 26th, 2018 17:00
model AFC1212DE
dell p/n D8794
Every time I cut it on it starts off normal and a question would the RAM have anything to do with it
speedstep
9 Legend
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47K Posts
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December 26th, 2018 22:00
Delta Electronics DC Brushless AFC1212DE, 12 Volt~1.60 Amp P8192, Model Number: B35502-35, Compatible Dell Part Number: D8794, Also Can Be Used In The Following Systems: Dimension 9150, 9200, XPS 400, XPS 410, Precision 380, 390, PowerEdge SC440, SC430
This is not an optiplex 755 fan
Y4574 Processor Fan GX520 GX620 320 330 360 740 745 755 760 780 960
Shutting down is power supply and or cooling issue
Souped
3 Posts
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December 22nd, 2019 18:00
Sometimes the PWM pin for a Dell fan or not, simply cannot regulate
the fan speed properly.
The exact solutions are,
To use a "Zalman Fanmate 1" a 3pin only on the
motherboard 4pin CPU fan port and plug the HSF-fan directly
into the fanmate1 - it will work and be adjustable, I did chop a
bit of plastic from the fanmate1 carefully to fit the plug better.
This solution also works for older xps 8100 and certain models
near this and keeps an excellent old Dell PC running without
too slow or over revving fans.
A person can just use a three pin fan, but must try several
(as I do) to get one the right speed, meaning slow enough to be quiet
and fast enough to cool.
speedstep
9 Legend
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47K Posts
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December 23rd, 2019 10:00
In the case of the 755 the wires are not standard. So if you need a standard fan you must use an adapter.
https://www.amazon.com/Pocaton-Female-Socket-Connector-Cooling/dp/B073XJV5L9/
The fan is not standard. The wiring is different. Plugging standard into 755 or the other way round can burn up the fan tach signal on the motherboard.
DELL FAN WIRING IS NOT STANDARD. DELL FAN CONVERSION.