Fortron 350W PSU fan replace - Variable or thermo controlled?

[Vanguardx]

I have the following power supply in my system:

Fortron FSP350-60PN
(see http://snipurl.com/fsp350_60PN and
http://snipurl.com/fsp350_newegg)

This is also referred to as their Aurora 350W PSU (see
http://snipurl.com/fsp350_aurora) because of the addition of the RPM
potentiometer for the 120cm fan (there is no blue LED in the model that
I got, and I don't want it glowing, anyway). I like Fortrons since they
are underrated for wattage. I believe this 350W PSU will punch out
413W.

The problem is fan noise but only when I try to up the RPM using the
potentiometer. The noise is not the typical buzz you hear from worn
bearings (this PSU has bearings instead of a sleeve). Rather than get a
buzz, there is a gurgle and the fan sounds erratic regarding its RPM,
like it is out of balance. When I attempt to up the RPM, airflow
increases slightly but not by much.

I have left the potentiometer at a low setting just below where the fan
starts to make noticeable noise. This still seems to provide for plenty
of airflow. The CPU runs at 47 degrees C and the system temp is 35
degrees C.

I have a thermo-controlled 80cm fan in the backpanel of the case. In
the morning, the computer is pretty quiet but the thermo fan starts to
spin faster as the system heats up after coming out of standby. I
figured that I'd up the Fortron's fan since the 120cm fan spinning
faster for more airflow should be quieter than speeding up an 80cm fan
to accomplish the same increase in airflow. If I get into overclocking
(and after replacing the CPU heat sink and use a slower-spinning but
higher airflow 120cm fan), I'll be even more acute to increasing the
airflow using the PSU fan.

I believe Fortron quit producing this model with the RPM potentiometer
because of problems but I'm not sure what were those problems. If the
problem were worn bearings, I'd still expect the fan speed to go up as I
rotate the potentiometer with increased noise. But once I get past a
threshold point where the fan used to start to make more noticeable air
noise going past its blades, now instead there is a gurgle or warbling
noise as though the fan is out of balance and airflow doesn't seem to
increase as I rotate the potentiometer. When I first got the Fortron
unit, it didn't do this. I could rotate the potentiometer through its
entire range, speed up and slow down the fan, and the noise from the air
movement would increase or decrease accordingly. Now when I try to up
the speed, it sounds like a pump trying to move water through it but
cavitating due to air in the system and the flow rate doesn't go up
appreciably.

Some articles refer to this unit as having a thermo-controlled fan but I
don't see anywhere that this model ever had one whether for the Aurora
series or not. I haven't the RPM go up as the temperature of the
exhaust went up (unless I manually rotate the RPM potentiometer). If I
send the PSU in under warranty, it will be weeks if not months before I
get it back. In that case, I'd rather just replace the PSU, send in to
the old one for warranty repair, and just stick it in storage upon
return. However, I'm pondering yanking out the potentiometer-controlled
120cm fan and sticking in a thermo-controlled 120cm fan (whose base
airflow rate would be equal to whatever is the current 120cm fan's
airflow rate at the low-speed end of the potentiometer).

I'd rather have fan speed be automatic rather than me monitoring and
adjusting fan speed. If the fan is thermo controlled in this PSU, I
haven't noticed it ever changing RPM on its own (so maybe that is what
is broke and interferes with the RPM potentiometer). That probably
means I would have to short across the potentiometer (since zero ohms is
probably where the fan would have max speed). I'd just unsolder it and
put in a jumper or just cut and splice the wires together and use
heatshrink to protect the spliced end. Anyone been inside a Fortron
with the RPM potentiometer to replace its fan? Anyone do what I'm
proposing (to eliminate the pot and use a thermo fan)?

I've have some experience using the Vantec thermo-controlled fans but
only the 80cm size. Are there better (and available) thermo-controlled
fans? Some users have complained the Vantec stealth fans have a
high-pitched whine (but no experience with the Vantec thermoflow fans).
As I recall, the Vantec 120cm thermoflow
(http://www.vantecusa.com/product-cooling.html#) fan has its thermistor
along the case of the fan so temperature is measure at the fan and you
can't affix it elsewhere, like on a heatsink for the voltage regulators
or wherever is hottest inside the PSU. The Antec 120cm
thermo-controlled fan (http://snipurl.com/antec_fan) also has its
thermistor in the fan case.

Does anyone know for sure if the 120cm fan in the Fortron is actually
thermally controlled (and the potentiometer is then simply an override
to up the RPM *over* what the thermister would use to speed up the fan)?

 

[kony]

I have the following power supply in my system:

Fortron FSP350-60PN
(see http://snipurl.com/fsp350_60PN and
http://snipurl.com/fsp350_newegg)

This is also referred to as their Aurora 350W PSU (see
http://snipurl.com/fsp350_aurora) because of the addition of the RPM
potentiometer for the 120cm fan (there is no blue LED in the model that
I got, and I don't want it glowing, anyway). I like Fortrons since they
are underrated for wattage. I believe this 350W PSU will punch out
413W.

The problem is fan noise but only when I try to up the RPM using the
potentiometer. The noise is not the typical buzz you hear from worn
bearings (this PSU has bearings instead of a sleeve). Rather than get a
buzz, there is a gurgle and the fan sounds erratic regarding its RPM,
like it is out of balance. When I attempt to up the RPM, airflow
increases slightly but not by much.

Are you certain it's a ball-bearing instead of sleeve? I've
had one of those opened an saw a Yate Loon sleeve bearing
fan in it, but it was the black-fan version, not a clear fan
like some have. The following pic shows a clear Yate Loon
fan though, but is too blurry for me to determine if it's
ball or sleeve (Yate Loon makes both). Peeling back the
sticker should reveal this.
http://www.silentpcreview.com/files/images/fortron1/aurora4.jpg


Normally I'm opposed to Yate Loon, if not all, sleeve
bearing fans but being a low RPM intake fan instead of
higher RPM exhaust it "should" normally last longer.
Point being, if it's possibly sleeve-bearing, try lubing it.

The next issue is whether you feel like modding it. If the
pot is intermittent you might see better results with a
fixed resistor or just shorting the pot's leads for full
RPM, IF the problem isn't the fan itself. You might remove
the fan and power it from another PSU in same horizontal
position to see if it acts the same.

I have left the potentiometer at a low setting just below where the fan
starts to make noticeable noise. This still seems to provide for plenty
of airflow. The CPU runs at 47 degrees C and the system temp is 35
degrees C.

I have a thermo-controlled 80cm fan in the backpanel of the case. In
the morning, the computer is pretty quiet but the thermo fan starts to
spin faster as the system heats up after coming out of standby. I
figured that I'd up the Fortron's fan since the 120cm fan spinning
faster for more airflow should be quieter than speeding up an 80cm fan
to accomplish the same increase in airflow. If I get into overclocking
(and after replacing the CPU heat sink and use a slower-spinning but
higher airflow 120cm fan), I'll be even more acute to increasing the
airflow using the PSU fan.

Due to having the PSU fan at a right angle and the reduction
by the grill at the back you may not see so much of a linear
flow increase from higher RPM. Also assess the case intake,
if it is sufficient or decreasing the exhaust rate.

I believe Fortron quit producing this model with the RPM potentiometer
because of problems but I'm not sure what were those problems. If the
problem were worn bearings, I'd still expect the fan speed to go up as I
rotate the potentiometer with increased noise. But once I get past a
threshold point where the fan used to start to make more noticeable air
noise going past its blades, now instead there is a gurgle or warbling
noise as though the fan is out of balance and airflow doesn't seem to
increase as I rotate the potentiometer.

You have two main suspects, the fan or the pot itself... the
suggestions I made above should help determine which is the
culprit.

When I first got the Fortron
unit, it didn't do this. I could rotate the potentiometer through its
entire range, speed up and slow down the fan, and the noise from the air
movement would increase or decrease accordingly. Now when I try to up
the speed, it sounds like a pump trying to move water through it but
cavitating due to air in the system and the flow rate doesn't go up
appreciably.

Some articles refer to this unit as having a thermo-controlled fan but I
don't see anywhere that this model ever had one whether for the Aurora
series or not. I haven't the RPM go up as the temperature of the
exhaust went up (unless I manually rotate the RPM potentiometer). If I
send the PSU in under warranty, it will be weeks if not months before I
get it back. In that case, I'd rather just replace the PSU, send in to
the old one for warranty repair, and just stick it in storage upon
return. However, I'm pondering yanking out the potentiometer-controlled
120cm fan and sticking in a thermo-controlled 120cm fan (whose base
airflow rate would be equal to whatever is the current 120cm fan's
airflow rate at the low-speed end of the potentiometer).

The arrow points to the fan control circuit board.
http://69.36.189.159/usr_1034/FSP300-60PN/fsp-speed.jpg

I'd rather have fan speed be automatic rather than me monitoring and
adjusting fan speed. If the fan is thermo controlled in this PSU, I
haven't noticed it ever changing RPM on its own (so maybe that is what
is broke and interferes with the RPM potentiometer). That probably
means I would have to short across the potentiometer (since zero ohms is
probably where the fan would have max speed). I'd just unsolder it and
put in a jumper or just cut and splice the wires together and use
heatshrink to protect the spliced end. Anyone been inside a Fortron
with the RPM potentiometer to replace its fan? Anyone do what I'm
proposing (to eliminate the pot and use a thermo fan)?

I should read ahead more often. ;-)
You can use a fan with it's own integral speed control but
it may not work right connected directly to the small fan
control circuit board, instead plug it directly into the
main PCB, where the fan control circuit board plugs in
(removing the fan control circuit entirely). You could just
short the pot instead, at the pot or the fan control
circuit, and use a non-thermally controlled fan and only the
PSU's circuit for control. You could attach the fan to the
circuit controller and put a median value resistor in place
of (instead of) the POT. There are several alternatives,
depending on what you want to do and the desired fan speed
(and the spec of the replacement fan IF lubing the original
isn't an option.

Also consider the case intake as mentioned previously, that
might be all that needs done to lower temp enough.

I've have some experience using the Vantec thermo-controlled fans but
only the 80cm size. Are there better (and available) thermo-controlled
fans? Some users have complained the Vantec stealth fans have a
high-pitched whine (but no experience with the Vantec thermoflow fans).

Yes they do whine some due to their ball-bearings. The
ideal replacement would be a fixed-speed, Panaflo, like a
FBA12A12L (Or FBA12A12M, the last character is speed... Low
Medium, High). "Usually" a Low would be enough without
speed control, but you would have to make that determination
though testing, and that particular model isn't very common,
may be hard to find.

As I recall, the Vantec 120cm thermoflow
(http://www.vantecusa.com/product-cooling.html#) fan has its thermistor
along the case of the fan so temperature is measure at the fan and you
can't affix it elsewhere, like on a heatsink for the voltage regulators
or wherever is hottest inside the PSU. The Antec 120cm
thermo-controlled fan (http://snipurl.com/antec_fan) also has its
thermistor in the fan case.

It's not necessarily a problem, the air temp would increase
too with heatsink temp rise. If you did need precise
control then that's what the POT was for... and if it is the
pot that's the problem you could replace it, OR just use a
fixed resistor instead. With such a large fan you might be
able to just leave it at a fixed speed though, provided you
can find an acceptible fixed-speed fan, or perhaps putting a
resistor or a few diodes in series on it's power lead.

Does anyone know for sure if the 120cm fan in the Fortron is actually
thermally controlled (and the potentiometer is then simply an override
to up the RPM *over* what the thermister would use to speed up the fan)?

Check the fan control circuit attached to the 'sink, there
should be a (green?) thermistor.

I'd try lubing the fan first if it's sleeve-bearing.

 

[Vanguardx]

Are you certain it's a ball-bearing instead of sleeve? I've
had one of those opened an saw a Yate Loon sleeve bearing
fan in it, but it was the black-fan version, not a clear fan
like some have.

I was told that it was a ball-bearing fan but I won't know until I
remove the PSU and open its case. At that point, I'll probably want to
have a replacement fan on hand since I would then just replace it. For
whatever fan that I put in (if I find the problem is with the fan and
not the pot), it'll be a ball-bearing fan although the hydrowave fans
sound interesting.

Normally I'm opposed to Yate Loon, if not all, sleeve
bearing fans but being a low RPM intake fan instead of
higher RPM exhaust it "should" normally last longer.
Point being, if it's possibly sleeve-bearing, try lubing it.

The problem is that the fan doesn't making the typical noise of a worn
sleeve or bearing. With those, as you up the RPM, the fan makes
progressively more noise. This fan almost sounds like it is out of
balance. The fan worked okay when I first got it but now trying to up
its RPM results in a cavitating noise like the spindle or blades are
bouncing around. I don't know how to better describe the sound. I've
had many fans go bad but never heard this noise before. Also, even when
a fan makes noise, it will usually still push air but this fan changes
very little for airflow rate as I rotate the potentiometer, but the fan
itself isn't speeding up, either.

The next issue is whether you feel like modding it. If the
pot is intermittent you might see better results with a
fixed resistor or just shorting the pot's leads for full
RPM, IF the problem isn't the fan itself. You might remove
the fan and power it from another PSU in same horizontal
position to see if it acts the same.

Thanks for the hint. Shorting the pot should be easy to see if the fan
will run at full tilt without the noise and to get full airflow. I
didn't think about laying it horizontal (to check if wear or looseness
was the culprit).

Potentiometers usually develop high-resistance spots if they are left in
one position all the time due to mini-arcing. Usually repeatedly wiping
the pots arm across its full range gets it clean. That trick didn't
work this time, plus I was moving the pot's arm to a different spot to
change the RPM. I suppose it could be the pot but usually the only
problems I've seen with those, other than physical abuse, is a spot goes
bad but wiping the arm repeatedly across the carbon track often works or
it gets damaged from too much current.

Due to having the PSU fan at a right angle and the reduction
by the grill at the back you may not see so much of a linear
flow increase from higher RPM. Also assess the case intake,
if it is sufficient or decreasing the exhaust rate.

When the PSU was new, rotating the pot and upping the RPM significantly
changed the airflow (and noise level). At the high end, the airflow was
higher than other PSUs that I use, probably due to the larger size
(120cm versus the typical 80cm). That backside of the Fortron is very
open, having more open area than the small honeycomb of metal. There is
only the one fan at the backside of the PSU for exhaust so I'm not quite
sure what you meant by a right-angle (other than the airflow through the
PSU itself).

I may add a front-side intake fan but that will be later. Right now,
I'll just focus on the PSU fan. Even with it running at slow speed
(where the PSU fan doesn't make the noise) and with the other exhaust
fan, temperatures are good.

The arrow points to the fan control circuit board.
http://69.36.189.159/usr_1034/FSP300-60PN/fsp-speed.jpg

Uffda. I figured they just used a pot to reduce voltage. Any idea what
they are doing to the fan with the RPM control PCB? Are they pulsing
the fan (at 12V) instead of just reducing the voltage? Does this PCB
maybe have voltage regulators to ensure the fan gets a minimal voltage
regardless of draw on the rails? Guess I'll have to trace where the
inputs to this PCB come from.

You can use a fan with it's own integral speed control but
it may not work right connected directly to the small fan
control circuit board, instead plug it directly into the
main PCB, where the fan control circuit board plugs in
(removing the fan control circuit entirely). You could just
short the pot instead, at the pot or the fan control
circuit, and use a non-thermally controlled fan and only the
PSU's circuit for control. You could attach the fan to the
circuit controller and put a median value resistor in place
of (instead of) the POT. There are several alternatives,
depending on what you want to do and the desired fan speed
(and the spec of the replacement fan IF lubing the original
isn't an option.

Actually I'd like to get rid of the pot altogether. I'd rather have the
PSU fan thermally controlled so it would up its RPM as the temperature
went up. However, the thermo fans that I've looked at don't provide the
thermistor on a lead so you can position it wherever would be most
appropriate.

Also consider the case intake as mentioned previously, that
might be all that needs done to lower temp enough.

Actually this came about by me trying to up the PSU fan speed to see if
it would exhaust some more of the heat rather than having the thermo
exhaust case fan speed up. The case fan is 80cm whereas the PSU fan is
120cm and I might get more airflow upping the 120cm fan but which might
not make as much noise as when the 80cm thermo fan speeds up. So far,
the temperatures look okay. It's just that I'd like the PSU fan to take
some of the load off the thermo case fan.

Check the fan control circuit attached to the 'sink, there
should be a (green?) thermistor.

I'd try lubing the fan first if it's sleeve-bearing.

Thanks for the helps and hints. Guess I'll have to check what that fan
PCB does, or choose to bypass it altogether.