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Can I make my power supply fan turn faster?



 
 
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  #1  
Old July 9th 18, 05:41 PM posted to alt.comp.hardware.pc-homebuilt
[email protected]
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Posts: 3
Default Can I make my power supply fan turn faster?

The fan is making noise. I can stop it with a pencil. I sprayed a
jet of wd 40. It is a little more quiet. I think if I could get it
spinning faster and give it one more burst, it might hit the spot.
  #3  
Old July 9th 18, 07:43 PM posted to alt.comp.hardware.pc-homebuilt
Paul[_28_]
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Posts: 731
Default Can I make my power supply fan turn faster?

lid wrote:
The fan is making noise. I can stop it with a pencil. I sprayed a
jet of wd 40. It is a little more quiet. I think if I could get it
spinning faster and give it one more burst, it might hit the spot.


That's exactly the wrong lubricant.

WD40 is a penetrating solvent, for loosening rusty this and that.

Even 3-in-1 oil, isn't an ordinary lubricating oil.
While it may indicate electric motors on the can,
it might not be the absolute best lubricant for the job.

The oil in your car, is getting closer to a real lubricating
oil. You need to select a viscosity for the job (too
thin, just pours out, too thick, it causes some
friction on the motor hub). for example, my old
tin of bicycle grease, the brown stuff, might
stick around... but it also might "stick around".
It would be hard to apply without a pressure fitting
and a pump.

In any case, you'll notice from overclocker threads,
that brushless DC cooling fans are voltage sensitive.
They spin slower at 7V than at 12V.

PWM (four wire, really small connector), those have
a speed control determined by the fourth wire. The
signals include

GND
+12V
RPM_signal (output) - two pulses per rotation
PWM signal (input) - square wave, duty cycle indicates desired speed

The CPU fan header on modern motherboards tends to have a PWM signal.

When the PWM signal is unconnected (plug four pin fan into
three pin motherboard), the fan spins full speed.

When you plug in a three pin fan to a four pin motherboard
header, everything is normal as far as the capabilities
of the fan go.

On older three wire fans, the signals are

GND
+12V
RPM_signal

and there is no speed control. Adjusting the 12V any where
between 7V and 12V provides a measure of speed control.
Maybe a ten year old motherboard, has a three pin connector
for the CPU fan, where the +12V power is adjustable.

Ventilation fans, such as remove air from the computer
case, have these fewer signals. There is no RPM signal available
to monitor whether the fan is spinning or not. These are
*very* common. Odds are, this is your fan. Note that,
this fan isn't practical to use on the CPU fan header,
because the motherboard will "whine" about no fan
being present, unless it sees RPM_signal pulses
coming out of the CPU fan. Generally the CPU fan is
the only fan header which is full-featured. Adjusting
the voltage on this, will control the speed.

GND
+12V

The ATX power supply doesn't have ready-made voltages
for lab experiments.

For the amount of dicking around it would take to
make you an "electronics lab" for this little
project, you might be able to pick up a replacement
cooling fan at the computer store. I realize in 2018,
there aren't a lot of good candidates. I was shocked
at the crap for sale at my one good computer store,
when I went looking for spares. I ended up with some
fans with ugly blue LEDs, which is not really what I
wanted.

The absolute best fan at the time a few years ago,
was Vantec Stealth. They've lasted nicely for *years*
here, but I don't think Vantec sells them any more.
Of the four speeds, low, medium, high, ultra, the
Stealth is a low. Your fan is probably a medium,
so that wouldn't be an exact substitute anyway.

High and ultra are too loud. I own one ultra, an impulse
buy, and it has a nice metal body. It runs around
110CFM and sounds like a mini vacuum cleaner.

The medium will be around 35CFM.

A low would be somewhat less than that.

The medium and low will be less than 30dBa. Fans
over that dBa level, have the potential to annoy.
To use the ultra, I used to run it at 7V. It's
currently out of the computer case, and some other
fan took its place.

The ultra was thicker. 37.5mm thick. Convention fans
are 25mm thick (one inch). Your fan will be conventional.
They do make 15mm fans, which are sometimes used on
low profile blow-down CPU coolers. The thinner the fan,
the less CFM cooling.

Fans also come in standard square dimensions. Such
as 80mm and 120mm. You need to measure the fan with
your inch ruler, and multiply by 25.4mm per inch.
Also, verify the four mounting holes for the
screws are in the standard locations. Some fans
do weird things with the corners, and you have
to keep your eyes peeled for stupid stuff. Fans
almost have defacto standards... except when they don't.

Sometimes you can guess at the energetics of the fan,
based on the current flow number printed on the fan
hub label. Like, if you took the fan to the computer
store, the clerk might look at the hub label, and the
overall design, to select a substitute for you.
My ultra is 1000mA. The Stealth might be 100mA.

There are a lot of fiddly little details, but nothing
you can't handle if you're observant.

Also, look at your motherboard manual, to see what
fan header capabilities you've got. Maybe simply turning
down the fan, via some BIOS setting will be enough.
Some BIOS had quite fancy thermistor versus RPM
rate controls, and they adjust the fans according
to thermal conditions. The SuperIO chip actually has
an automated "thing" to do that.

Or in Windows, use Almico Speedfan (which will re-program
the registers on the SuperIO). If you have PWM
or motherboard voltage control fan headers, you could
turn the fan down a notch and see if the noise stops.

http://www.almico.com/speedfan452.exe

( http://www.almico.com/sfdownload.php )

Speedfan can only control fan speed, if the motherboard
fan headers have the right electronics to support speed
changing. Don't expect miracles. From a percentages
and betting perspective, most chassis cooling fans
won't respond to a Speedfan setting. If you have
a primo setup, you might get lucky :-)

Most of the time, the confluence of factors means
that fan you didn't describe in detail, doesn't
actually have speed control. And you have to be
handy with a soldering iron, if you want to prove
them wrong.

You can get a rheobus for a 5.25" tray in the
computer, and it comes with knobs you turn to
adjust fan speed. But these have gone out of
favor, and there might not be much on a site
like Newegg to choose from. Only a couple
designs were exemplary, having a 2 amp per
channel control capability, and those could
handle anything. The rest were "schlock" and
had wire-wound pots or something, a really cheap
and not so good method. The cheesy ones could
burn out easier.

This is a sample of a rheobus. OK, great, it
has eight channels. It's 8 channels for $85.
If they'd made a 4 channel one, it would be
$42 bucks. And if they made a 2 channel one
(enough for the cheapest computerist), they
could have made this for $21 bucks. I bet
they've sold zero of these... "Maybe Bill Gates
owns one." Still, their heart is in the
right place, as it has a 30W per channel rating
(a bit more than 2 amps at 12V).

https://www.newegg.com/Product/Produ...9SIA17P5RA7928

Paul
  #5  
Old July 9th 18, 09:57 PM posted to alt.comp.hardware.pc-homebuilt
VanguardLH[_2_]
external usenet poster
 
Posts: 1,262
Default Can I make my power supply fan turn faster?

no wrote:

The fan is making noise. I can stop it with a pencil. I sprayed a
jet of wd 40. It is a little more quiet. I think if I could get it
spinning faster and give it one more burst, it might hit the spot.


Is the PSU out of warranty? My guess is Yes as the fan is making noise
which happens after the warranty expires. Hopefully the fan goes bad a
long time after the warranty but that depends on the quality of the fan
which depends on the qualify of the PSU. Expect crappy fans in cheap
PSUs. You definitely get what you pay for (if you buy the PSU to build
your own) and pre-builts often come with crappy PSUs (whatever is
minimal to handle the spec load of a model and for a MTBF that is just
longer than the warranty).

Measure the diameter of the fan. Buy a new one. After the new fan
arrives, remove the PSU and open it up. Spin the blade hub by hand.
Does rotate several times or does it stop in under 1 or 2 rotations?
Does it feel free as you rotate the blades by hand or can you feel
resistance (wear)? If the fan rotates freely, use an ear swab with
isopropyl alcohol to clean the fan blades on both sides. Check if the
fan is now quiet since filth on the blades (that you cannot blast off
with a compressed air can) can throw it out of balance and cause noise;
however, if it has been going on for a long time, the bearing has gotten
worn with an out-of-balance fan. Oiling the bearing with silicone spray
(WD-40 was the worst you could use) might make it quieter until the
lubricant oozed out of the bearing to let it start wobbling again. If
it was a cheap PSU, it could have a sleeve bearing fan which means the
lube will ooze out. Sleeve fans are only good for vertical use.

Since you'll have to open the PSU to get at the fan to properly lube it
(spraying lube at the fan will NOT lubricate the bearing but instead
change its balance) or clean it or both, you're already right there
inside and might as well as replace the fan. That's why I first
mentioned getting a new fan. Do NOT get a sleeve type fan as those are
designed for vertical operation, not horizontal as in a PSU. Get a
ball-bearing type fan. Those will last about 6-8 years. Fluid/hydro
fans are good, are more costly, and last 10 years, or longer. Consider
how much longer you will have the computer. Remember the cheaper you go
on a fan then the more likely it will fail sooner. Noctua are pricey
but that's what I end up putting in my builds and when I have to replace
a PSU fan (video card fans are often very specialized, especially if
shrouded, so you're stuck getting a duplicate for replacement).

You may not find a replacement fan that has the same connector to mate
with the header on the PCB inside the PSU. Likely it is just a 2-wire
fan unless it can be speed controlled (which is a 3-wire fan). Likely
you will need to remove the old fan by snipping its wires near the fan
to reuse with heat shrink tubing and solder to splice on the new fan.
Make sure the now longer wiring doesn't get into the new fan's blades.

If you don't know how to use a heat gun with heatshrink tubing and do
soldering, get a new PSU.
  #6  
Old July 9th 18, 10:21 PM posted to alt.comp.hardware.pc-homebuilt
Rene Lamontagne
external usenet poster
 
Posts: 108
Default Can I make my power supply fan turn faster?

On 07/09/2018 3:57 PM, VanguardLH wrote:
no wrote:

The fan is making noise. I can stop it with a pencil. I sprayed a
jet of wd 40. It is a little more quiet. I think if I could get it
spinning faster and give it one more burst, it might hit the spot.


Is the PSU out of warranty? My guess is Yes as the fan is making noise
which happens after the warranty expires. Hopefully the fan goes bad a
long time after the warranty but that depends on the quality of the fan
which depends on the qualify of the PSU. Expect crappy fans in cheap
PSUs. You definitely get what you pay for (if you buy the PSU to build
your own) and pre-builts often come with crappy PSUs (whatever is
minimal to handle the spec load of a model and for a MTBF that is just
longer than the warranty).

Measure the diameter of the fan. Buy a new one. After the new fan
arrives, remove the PSU and open it up. Spin the blade hub by hand.
Does rotate several times or does it stop in under 1 or 2 rotations?
Does it feel free as you rotate the blades by hand or can you feel
resistance (wear)? If the fan rotates freely, use an ear swab with
isopropyl alcohol to clean the fan blades on both sides. Check if the
fan is now quiet since filth on the blades (that you cannot blast off
with a compressed air can) can throw it out of balance and cause noise;
however, if it has been going on for a long time, the bearing has gotten
worn with an out-of-balance fan. Oiling the bearing with silicone spray
(WD-40 was the worst you could use) might make it quieter until the
lubricant oozed out of the bearing to let it start wobbling again. If
it was a cheap PSU, it could have a sleeve bearing fan which means the
lube will ooze out. Sleeve fans are only good for vertical use.

Since you'll have to open the PSU to get at the fan to properly lube it
(spraying lube at the fan will NOT lubricate the bearing but instead
change its balance) or clean it or both, you're already right there
inside and might as well as replace the fan. That's why I first
mentioned getting a new fan. Do NOT get a sleeve type fan as those are
designed for vertical operation, not horizontal as in a PSU. Get a
ball-bearing type fan. Those will last about 6-8 years. Fluid/hydro
fans are good, are more costly, and last 10 years, or longer. Consider
how much longer you will have the computer. Remember the cheaper you go
on a fan then the more likely it will fail sooner. Noctua are pricey
but that's what I end up putting in my builds and when I have to replace
a PSU fan (video card fans are often very specialized, especially if
shrouded, so you're stuck getting a duplicate for replacement).

You may not find a replacement fan that has the same connector to mate
with the header on the PCB inside the PSU. Likely it is just a 2-wire
fan unless it can be speed controlled (which is a 3-wire fan). Likely
you will need to remove the old fan by snipping its wires near the fan
to reuse with heat shrink tubing and solder to splice on the new fan.
Make sure the now longer wiring doesn't get into the new fan's blades.

If you don't know how to use a heat gun with heatshrink tubing and do
soldering, get a new PSU.


WARNING !!!!!! IF you open up the PSU be warned that the large Caps can
store a very dangerous Voltage. If your not familiar with This stuff,
leave it alone and buy a new PSU.

Rene

  #7  
Old July 10th 18, 10:28 AM posted to alt.comp.hardware.pc-homebuilt
Steve Hough
external usenet poster
 
Posts: 12
Default Can I make my power supply fan turn faster?

Rene Lamontagne was thinking very hard :

WARNING !!!!!! IF you open up the PSU be warned that the large Caps can store
a very dangerous Voltage. If your not familiar with This stuff, leave it
alone and buy a new PSU.

Rene


Indeed. As the o/p has already managed to squirt the wrong oil into it.
I'm surprised so many others here advocated opening the thing up. And
if he waas familiar with this stuff, I doubt he would have uses WD40 in
the first place.
  #8  
Old July 10th 18, 12:18 PM posted to alt.comp.hardware.pc-homebuilt
Paul[_28_]
external usenet poster
 
Posts: 731
Default Can I make my power supply fan turn faster?

Steve Hough wrote:
Rene Lamontagne was thinking very hard :

WARNING !!!!!! IF you open up the PSU be warned that the large Caps
can store a very dangerous Voltage. If your not familiar with This
stuff, leave it alone and buy a new PSU.

Rene


Indeed. As the o/p has already managed to squirt the wrong oil into it.
I'm surprised so many others here advocated opening the thing up. And if
he waas familiar with this stuff, I doubt he would have uses WD40 in the
first place.


If the fan is soldered to the PCB, I would not
attempt to replace the fan.

If the fan uses a connector, you may be able to
unplug the connector. The most dangerous part,
is trying to use tools to torque the connector
to get it loose. If a tool slips off, it could
hit a high voltage item.

In any case, this is one reason the fan connector
is on the periphery of the PCB and not in the
middle of it. You don't have to get "up close
and personal" with the main cap, to change out
a fan.

*******

There is as much danger in making the main caps
"safe", as there is in working around the main
caps.

To see which caps are dangerous, there is a sample
schematic here. Modern PSUs don't use the same
architecture (they do double forward conversion),
but in terms of safety issues, this is a good
primer.

http://www.pavouk.org/hw/en_atxps.html

Capacitor C5 and C6 are larger devices (tin cans),
which are charged to 300VDC or higher. If you work
out 1/2*C*V^2 , the number of joules involved
is similar to that of a microwave oven cap.
*Do not* stick a screwdriver across the two
wire ends of a C5 or C6 cap, as the noise
is loud enough you could lose an eardrum.

1/2 * 0.000470 * 300 * 300 = 21 Joules

Resistor R2 and R3 are bleeder resistors. They're
in the circuit, to drain C5 and C6 after about
an 8 minute delay. That's a safety feature.
If we didn't need safety, R2 and R3 would not
even be in the circuit. They only have one
reason for being there. (I count waiting five
time constants as being long enough.)

But technicians working on a circuit like this,
assume R2 and R3 are defective and have gone
open circuit. And they further assume C5 and C6
are fully charged (it's a bit like defusing a bomb).
If a technician wanted to solder something on
the bottom of the PCB of the power supply, they
would use an *external* bleeder resistor to quietly
(and slowly) discharge C5 and C6. There is always
the danger of getting a shock, while making the
caps safe! (If you make a bleeder, you make yourself
some Plexiglas handles to position it, and
so on.)

If I see that the fan connector is "off to the side"
and I can work on the low voltage fan connector
without getting near C5 and C6, I'll do that.
If the fan is soldered to the PCB, I would probably
decline to work on the project and just buy a new PSU.

I only got one decent shock in all my time
doing electronics. I got my "teaching" shock as a kid,
working with an ignition coil. One minute I was
at the workbench, the next minute I was getting
myself off the floor, and I apparently had
jumped backwards and hit the floor when the
shock got me. I'd laid something on top of some
wires, and didn't see a HV wire underneath something
else, and that's how my little experiment "got me" :-(

I've worked on high voltage since then, with
no other incidents to report. For example, I
have a flyback circuit with a tripler on the output,
for HV work, and that circuit has never managed
to get me. It would likely burn as much as shock.
But the reason I've not had a shock since, is
the first lesson was *the best* :-) You couldn't
ask for a better lesson. I presume I passed out
for a moment, but I'm not really sure. Because
I don't know exactly how I hit the floor.

Some of my other experiments as a kid, did more damage.
That one wasn't the worst. A good lesson is one
you learn without bleeding or a concussion.

Paul
  #9  
Old July 10th 18, 12:26 PM posted to alt.comp.hardware.pc-homebuilt
Steve Hough
external usenet poster
 
Posts: 12
Default Can I make my power supply fan turn faster?

Paul has brought this to us :
Steve Hough wrote:
Rene Lamontagne was thinking very hard :

WARNING !!!!!! IF you open up the PSU be warned that the large Caps can
store a very dangerous Voltage. If your not familiar with This stuff,
leave it alone and buy a new PSU.

Rene


Indeed. As the o/p has already managed to squirt the wrong oil into it. I'm
surprised so many others here advocated opening the thing up. And if he
waas familiar with this stuff, I doubt he would have uses WD40 in the first
place.


If the fan is soldered to the PCB, I would not
attempt to replace the fan.

While you are patently very knowledgeable on electronics, is it not
possible sometimes to answer people with just one sentence. When it
comes to the o/p, I would just presume that someone who just squirts
the wrong oil in and hopes, is too stupid to be openeing up a PSU.
 




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