I'm looking to replace the fan in my power supply.

[RockGuitarDude]

I have it so all my intakes, cpu, and video card fans are sufficiently quiet. Next is to tackle the power supply fan. I'm concerned solely because of the voltages involved and I don't wanna blow up my rig...

I have a 300Watt antec power supply which came with my case. I have a fan made by MAD DOG which is spec'ed at 27 CFM. Is it safe to change it? Is this a really sensitive issue or does the power supply have some sort of safety mechanism? Also, is it super sensitive to temerature increases and what not or is it kind of like, as long as there is some decent air flow, it will be enough.

 

[Granorense]

Hopefully this will help you, do it on your own risk. I will not be liable for any missing arms, fingers or your life. I do it all the time, but i am extremely careful.

Text

 

[Zepper]

Yeah, 27 CFM should be plenty for a PSU. Remember in the old days of PCs the ONLY fan in the case was the PSU fan, so it had to be strong enough to both keep the PSU cool and to draw sufficient air through the rest of the case. Now usually all it needs to do is cool the PSU, but you have to spec it based on your situation. If it is still the only exhaust fan in your case, then maybe you want to look for a stronger one - say 35 CFM or so.
. Also if you hook it up the same way as your current PSU fan, it may be connected to a temp speed control which may make your new fan run too slow to keep even the PSU cool. Then you will want to either bypass the speed control (connect the red lead directly to +12V) or bring the fan lead out of the PSU case and connect it to a manual speed control like the Zalman Fan Mate or rig your own with an appropriate potentiometer.
. I also have done something that I call a "Turbo Exhaust". This uses a fan adapter ( 80 to 90 or 120 mm) mounted on the OUTSIDE rear of the PSU case. And then use a BIG fan that can really blow that sucker out and still be fairly quiet... You bring the fan's power lead into the PSU right thru the throat of the adapter.
.bh.

Have a :beer: !

 

[RockGuitarDude]

I have it hooked up with an 80mm intake at front, 80mm out at rear, and i want to put the third of the same fan in the power supply... It "says" 27 cfm (I don't know how much this really means with companies lying all the time lol)... I just don't really know if this is approriate and I want more input from others before I do it.

 

[HardWarrior]

Just be very careful. Even an unplugged PSU has enough capacitor charge to kill you.

 

[RockGuitarDude]

Yeah thanks for the warning. I am aware of all the risks involved in actually doing the procedure but I am unaware of how well my 27CFM will perform as it is the only fan in the psu and I see a lot of them with 2 fans.

 

[Zepper]

27CFM is over 240 exchanges of the volume of air within your PSU per minute - or 4 times per second! That's plenty. And it's usually the noise figure that is off on fan specs not the CFM.
.bh.

 

[HardWarrior]

Originally posted by: RockGuitarDude
Yeah thanks for the warning. I am aware of all the risks involved in actually doing the procedure but I am unaware of how well my 27CFM will perform as it is the only fan in the psu and I see a lot of them with 2 fans.

Why not spend a few bucks extra an have a compUSA tech-stiff do it for you?

 

[RockGuitarDude]

Originally posted by: Zepper
27CFM is over 240 exchanges of the volume of air within your PSU per minute - or 4 times per second! That's plenty. And it's usually the noise figure that is off on fan specs not the CFM.
.bh.

True, but who can ya trust these days.. lol

 

[RockGuitarDude]

Originally posted by: HardWarrior

Originally posted by: RockGuitarDude
Yeah thanks for the warning. I am aware of all the risks involved in actually doing the procedure but I am unaware of how well my 27CFM will perform as it is the only fan in the psu and I see a lot of them with 2 fans.

Why not spend a few bucks extra an have a compUSA tech-stiff do it for you?

I wire things up in my engineering classes all the time so I'm more than capable. My only concern is if it is enough air flow and I'm just taking extra caution since it is capable of destroying my entire computer if something goes wrong, which would make me sad.

 

[Granorense]

Originally posted by: RockGuitarDude

Originally posted by: HardWarrior

Originally posted by: RockGuitarDude
Yeah thanks for the warning. I am aware of all the risks involved in actually doing the procedure but I am unaware of how well my 27CFM will perform as it is the only fan in the psu and I see a lot of them with 2 fans.

Why not spend a few bucks extra an have a compUSA tech-stiff do it for you?

I wire things up in my engineering classes all the time so I'm more than capable. My only concern is if it is enough air flow and I'm just taking extra caution since it is capable of destroying my entire computer if something goes wrong, which would make me sad.

Besides, nothing like doing yourself.

 

[RockGuitarDude]

I think I made a mistake! I incorrectly identified the psu as the source of the noise. It's actually really quiet. The culprits are my hard drives. Maybe I'll try my hand at some rubber insolation for them.

 

[Varun]

I made the same mistake. I thought my video card fan was a bit loud, but when I removed it and booted the PC, I found my 4 year old Maxtor was the culprit. The bearings are whining at a piercing pitch.

I ordered a new Samsung to replace it.

If your drives are old, it may be a good idea to replace them, but if they are new, I guess there are a couple of things to try before an enclosure.

 

[RockGuitarDude]

My Western Digital 60 gig is 2 years old... but my 8 Gig hard drive is from a HP Celeron 466Mhz machine... i'll have to do some investigation into this...

 

[0roo0roo]

i use a fan controller. just be reasonable. and watch temps, if the psu starts spitting out extremely hot air(unlikely) it ussually just means ur case ventilation is really really bad...

psu's tend to be made for worst case scenarios anyways.. the pc with only psu as case cooler

 

[skywalker66]

I dont get quite what the big deal is about taking apart a PSU and replacing the fan.

I mean I've heard stuff about the capacitors containing lethal charges, even after its been unplugged, but what does this mean?

Like if you leave it unplugged for like 15 minutes dont the capacitors lose their charge?

And where is it, that you'll get shocked if you touch? Is it anywhere on the capacitor or just the part where it connects to the PCB board?

 

[RockGuitarDude]

They could hold the charge for quite a while and it's hard to say when they are gone for sure unless you discharge it to ground. It would only affect you if you were to touch one of the leads out of the capacitor though.

 

[ROcHE]

Unplug the psu. Turn on the computer. The fan will spin for a second or so. This should discharge the capacitors. That's what I do. Dunno if it's good but I'm not dead yet and I've taken apart a couple of PSUs.

 

[HardWarrior]

Originally posted by: ROcHE
Unplug the psu. Turn on the computer. The fan will spin for a second or so. This should discharge the capacitors. That's what I do. Dunno if it's good but I'm not dead yet and I've taken apart a couple of PSUs.

Capacitors can hold a hard charge for months and months. A fan spinning for a couple of seconds won't discharge the ones found in your average PSU.

 

[ROcHE]

Originally posted by: HardWarrior

Originally posted by: ROcHE
Unplug the psu. Turn on the computer. The fan will spin for a second or so. This should discharge the capacitors. That's what I do. Dunno if it's good but I'm not dead yet and I've taken apart a couple of PSUs.

Capacitors can hold a hard charge for months and months. A fan spinning for a couple of seconds won't discharge the ones found in your average PSU.

What is discharging then?