[SOLVED] Help: TX850M Fan Speed Changes When Powering Up

Noxious1

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Nov 28, 2019
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Hi,

I just replaced my psu with a
corsair TX850M
and if i turn it on it will be normal fan speed
then if i turn it off then back on next time its at high speed :/

so if i want to put it back to normal
i got to turn off my pc again then back on just to get it back to normal speed..

any solutions?
 
Solution
It would only make any sense to me if the caps on the 12v rail were fully discharging, and if something in the psu was hanging up on shutdown, and if the in rush at first boot was enough to overheat something right next to whatever is used as a temp sensor for the fan, and if the fan was responding to that incorrect initial temp, and if on reboot the psu is not coming out of standby mode, and if whatever is hanging up now isnt, and if the caps are not drained or discharged yet, meaning if the in rush is far less, it's not now pinging the sensor. If that makes sense, because a reboot isn't a full shutdown of the hardware, it's only a reset of the software. The psu doesn't go...
Hi,

I just replaced my psu with a
corsair TX850M
and if i turn it on it will be normal fan speed
then if i turn it off then back on next time its at high speed :/

so if i want to put it back to normal
i got to turn off my pc again then back on just to get it back to normal speed..

any solutions?

Can you rephrase this?

Turn it on from when?

Turn it off how?

Turn it back on how?

The TX-M fan speed is completely dependent on the temperature of the PSU. So what you're saying doesn't make much sense. Are you sure what you're hearing is the PSU fan?
 
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Noxious1

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Nov 28, 2019
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Can you rephrase this?

Turn it on from when?

Turn it off how?

Turn it back on how?

The TX-M fan speed is completely dependent on the temperature of the PSU. So what you're saying doesn't make much sense. Are you sure what you're hearing is the PSU fan?


so for example if my pc is off and i go to turn it on the psu fan will be on full speed right away and stay full speed untill i turn the pc off and back on again.
(how: power button on the front)

-never had this issue with my tx850 but now that i upgraded to the tx850M its happening-
 
so for example if my pc is off and i go to turn it on the psu fan will be on full speed right away and stay full speed untill i turn the pc off and back on again.
(how: power button on the front)

-never had this issue with my tx850 but now that i upgraded to the tx850M its happening-

Ok. So you turn the PC on with the power button on the case and the PC doesn't POST. You just hear the fan spinning really fast, but nothing else. Then, when you turn it off and turn it back on again, again from the power button on the case, everything powers up normally.

And you've opened up the PC and watched the PSU fan spin up really fast and that's why you're 100% sure it's the PSU fan doing this?
 

Karadjgne

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Ambassador
The psu fan is generally upside down, inside its case, buried inside your case. The chances you can be certain it's the psu fan you can hear over-riding the noise put out by the case fans, cpu fan(s) and gpu fans at startup is relatively slim in the extreme.

Holding the power button down for shutoff is a cmos reset. It bypasses the cmos tables entirely and forces the bios to do a full discovery of all included hardware and drivers. To accomplish that, loads are set deliberately high on everything, all controlled fans will start at high rpm. The psu fan is not a controlled by bios fan, and will only spin up as fast as its own thermal controller requires. Every other fan in the pc will be @ 50% to 100% duty cycle.

Using Windows Shutdown, cmos is used at boot, so prior settings for fans and other hardware are used, so no need for bios discovery or high load usage.
 
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Noxious1

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Nov 28, 2019
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Ok. So you turn the PC on with the power button on the case and the PC doesn't POST. You just hear the fan spinning really fast, but nothing else. Then, when you turn it off and turn it back on again, again from the power button on the case, everything powers up normally.

And you've opened up the PC and watched the PSU fan spin up really fast and that's why you're 100% sure it's the PSU fan doing this?


no nots at all

the pc runs absoulty fine.. just the psu fan spins really fast and for me to stop it i have to turn the pc off and back on again to make it stop
 

Noxious1

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Nov 28, 2019
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You're POSITIVE that it's the PSU fan that you're hearing?

The PSU fan is thermally controlled. It doesn't make sense that on one boot up the fan would spin full speed and then not the next time.

100% sure
i just did a bios update and hopefully that sorts it but 1million % sure is psu fan and its fresh not even a week old
 

Karadjgne

Titan
Ambassador
It would only make any sense to me if the caps on the 12v rail were fully discharging, and if something in the psu was hanging up on shutdown, and if the in rush at first boot was enough to overheat something right next to whatever is used as a temp sensor for the fan, and if the fan was responding to that incorrect initial temp, and if on reboot the psu is not coming out of standby mode, and if whatever is hanging up now isnt, and if the caps are not drained or discharged yet, meaning if the in rush is far less, it's not now pinging the sensor. If that makes sense, because a reboot isn't a full shutdown of the hardware, it's only a reset of the software. The psu doesn't go back into standby mode, it remains active, the only difference being the amount of load on the rails.

But that's a lot of IF's and I've yet to see the planets all line up in unison in a perfect eclipse, but I suppose it can happen eventually. Murphys law says so.
 
Solution

Noxious1

Reputable
Nov 28, 2019
29
1
4,535
It would only make any sense to me if the caps on the 12v rail were fully discharging, and if something in the psu was hanging up on shutdown, and if the in rush at first boot was enough to overheat something right next to whatever is used as a temp sensor for the fan, and if the fan was responding to that incorrect initial temp, and if on reboot the psu is not coming out of standby mode, and if whatever is hanging up now isnt, and if the caps are not drained or discharged yet, meaning if the in rush is far less, it's not now pinging the sensor. If that makes sense, because a reboot isn't a full shutdown of the hardware, it's only a reset of the software. The psu doesn't go back into standby mode, it remains active, the only difference being the amount of load on the rails.

But that's a lot of IF's and I've yet to see the planets all line up in unison in a perfect eclipse, but I suppose it can happen eventually. Murphys law says so.


i shall try record it
 

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