PSU fan mod question

[kyn1972]

Thinking about replacing the fan in a Seasonic PSU I picked up with a RGB fan and am wondering if I have to mod the fan so it can connect to the PSU fan port or can I simply mod it to connect directly up to a fan header on my motherboard?

[Analog]

1 minute ago, kyn1972 said:

Thinking about replacing the fan in a Seasonic PSU I picked up with a RGB fan and am wondering if I have to mod the fan so it can connect to the PSU fan port or can I simply mod it to connect directly up to a fan header on my motherboard?

Generally there are three to four wires that come from any fan in order to power it up. If the connector of the new fan doesn't match the one of the power supply (many times power supplies have proprietary fan headers) you can simply splice in the wires. The RGB connector will need to be plugged into a header on your motherboard though.

 

 

[Bombastinator]

2 minutes ago, kyn1972 said:

Thinking about replacing the fan in a Seasonic PSU I picked up with a RGB fan and am wondering if I have to mod the fan so it can connect to the PSU fan port or can I simply mod it to connect directly up to a fan header on my motherboard?

Conventional wisdom is dont.  inside the PSU is far and away the most dangerous part of a computer.  Computers work off low voltage DC, so it’s pretty hard to electrocute yourself. PSUs deal with converting high voltage AC to the low voltage DC, and to do it they use some pretty big capacitors.  They can be dangerous even after they’ve been unplugged.  I opened a PSU once but I removed it from the machine and let it sit around for a month before I unscrewed things.  I wanted to fix a fan too.  Turned out to be a huge pita.  The fan I though was 120mm was 110mm and 120s didn’t fit. Also the fan used a different smaller form of molex.  

[kyn1972]

1 minute ago, Analog said:

Generally there are three to four wires that come from any fan in order to power it up. If the connector of the new fan doesn't match the one of the power supply (many times power supplies have proprietary fan headers) you can simply splice in the wires. The RGB connector will need to be plugged into a header on your motherboard though.

 

 

 I know will have to splice if I connect it to the PSU as the PSU is only two wires and the fan is a 4 wire one but the question is do I have to do it or can I power the fan externally instead?

[kyn1972]

2 minutes ago, Bombastinator said:

Conventional wisdom is dont.  inside the PSU is far and away the most dangerous part of a computer.  Computers work off low voltage DC, so it’s pretty hard to electrocute yourself. PSUs deal with converting high voltage AC to the low voltage DC, and to do it they use some pretty big capacitors.  They can be dangerous even after they’ve been unplugged.  I opened a PSU once but I removed it from the machine and let it sit around for a month before I unscrewed things.  I wanted to fix a fan too.  Turned out to be a huge pita.  The fan I though was 120mm was 110mm and 120s didn’t fit. Also the fan used a different smaller form of molex.  

Should it not be a straight forward mod though? After all I am not attempting to fix, remove or change any of the components of the PSU itself other than the fan which plugs into a fan port inside the PSU.

[Bombastinator]

2 minutes ago, kyn1972 said:

 I know will have to splice if I connect it to the PSU as the PSU is only two wires and the fan is a 4 wire one but the question is do I have to do it or can I power the fan externally instead?

The PSU is a single isolated unit in ATX.  The PSU controls it’s own fam itself and it is not required to conform to any standard. If you run the wires out of the fan box I suppose you could control it from the motherboard instead.  You’ll have to guess at what internal temps are because there isn’t any standardized connection for PSU thermocouples in ATX. 

[Bombastinator]

1 minute ago, kyn1972 said:

Should it not be a straight forward mod though? After all I am not attempting to fix, remove or change any of the components of the PSU itself other than the fan which plugs into a fan port inside the PSU.

Heh.  Shoulda woulda coulda.  Might be.  Might not.  All depends on what the sea sonic engineer that designed the thing felt like that day.

[kyn1972]

1 minute ago, Bombastinator said:

The PSU is a single isolated unit in ATX.  The PSU controls it’s own fam itself and it is not required to conform to any standard. If you run the wires out of the fan box I suppose you could control it from the motherboard instead.  You’ll have to guess at what internal temps are because there isn’t any standardized connection for PSU thermocouples in ATX. 

Well I was planning on simply running the fan constantly when I am on the computer along with my other fans all of which are Sickelflow fans by Cooler Master as my PC is powered off when I am not using it.

[manikyath]

the problem with replacing the fan in a power supply is that you essentially lose any guarantee about the thermal performance of the power supply. if you're not getting anywhere near the rated power of the power supply it's probably fine, but i wouldnt do it with a PSU you're running right on the edge.

 

i have a psu with a modified fan in one of my low power boxes, the way i did it (because the PSU fan is the only fan in the system) is to hook up the fan to both PSU and cpu fan header with diodes in between, so that it'll always spin at the highest of the two settings. Although if you dont have parts on hand or the skill to assemble that... it's best you just dont.

 

all in all, the 'cleanest' solution is to splice the fan into the power supply's fan control, but the easiest is to just power it from your motherboard, and set your fan curve a bit more aggressive, so that the PSU will have propper cooling.

[thrasher_565]

12 hours ago, Bombastinator said:

Conventional wisdom is dont.  inside the PSU is far and away the most dangerous part of a computer.  Computers work off low voltage DC, so it’s pretty hard to electrocute yourself. PSUs deal with converting high voltage AC to the low voltage DC, and to do it they use some pretty big capacitors.  They can be dangerous even after they’ve been unplugged.  I opened a PSU once but I removed it from the machine and let it sit around for a month before I unscrewed things.  I wanted to fix a fan too.  Turned out to be a huge pita.  The fan I though was 120mm was 110mm and 120s didn’t fit. Also the fan used a different smaller form of molex.  

i shocked my self once on the inside of a psu one too. at school we made amps and i decided to add a pc psu to power the fan and led...

 

ya the can be 120, 140, 135, or other odd sizes

[Bombastinator]

3 hours ago, thrasher_565 said:

i shocked my self once on the inside of a psu one too. at school we made amps and i decided to add a pc psu to power the fan and led...

 

ya the can be 120, 140, 135, or other odd sizes

Apparently the big danger with PSUs is the capacitors.  They can hold enough charge and dump it fast enough to actually kill, which is something a regular household AC outlet normally has trouble doing.  This is completely ignoring the whole explosion thing which capacitors are also known for. 

[thrasher_565]

16 minutes ago, Bombastinator said:

Apparently the big danger with PSUs is the capacitors.  They can hold enough charge and dump it fast enough to actually kill, which is something a regular household AC outlet normally has trouble doing.  This is completely ignoring the whole explosion thing which capacitors are also known for. 

ya that's what shocked me

[kyn1972]

Mod went fine.

Simply created a small notch to run the power and rgb wires through and plugged it in and everything is working and it looks awesome as the PSU sits on its side with the fan facing the case window.

 

[seon123]

2 hours ago, kyn1972 said:

Mod went fine.

Simply created a small notch to run the power and rgb wires through and plugged it in and everything is working and it looks awesome as the PSU sits on its side with the fan facing the case window.

 

The most important issue, which you still haven't addressed in any way, is that the fan will be worse than the stock one. The crappy Hong Hua fan, for all its issues, at least moves enough air with the fan curve on the PSU. Whatever crappy RGB fan you downgraded to will move less air, and the PSU is not designed to use it. Even a mUh NoCtUa fan would be worse, as the fan in a PSU needs a lot of static pressure. Unless you put a couple of dozen of thermocouples everywhere inside the PSU and checked that the temperatures are actually fine, you just don't know if "the mod went fine".

[SansVarnic]

-= Moved to Power Supplies =-

Probably better suited here.