# can you take the psu out of the psu



## keakar (Sep 18, 2007)

i was wondering why cant you take the psu circuit board out of the psu case and mount it at the bottom of the case and put a 120mm fan blowing over it.

shouldnt it run cooler and much quieter that way?

a pair of 80mm fans would fill the psu hole left by the missing psu.

i seems the airflow for psu is so inefficient that opening the box to allow air to move across it would help.


----------



## DaMulta (Sep 18, 2007)

You can, just don't touch anything in there. It hurts really really bad. You just have to trust me on that one.


----------



## lemonadesoda (Sep 18, 2007)

Dont do it. The thick case of the PSU does 2 things:

1./ Creates an earthed cage around the PSU components. This stops A LOT of e-noise.

2./ Keeps fingers (and dust and other objects) away from hi-voltage components.

WHY DO IT?  It won't run cooler or quieter if you add extra fans. It will only blow the heat OVER THE CPU.  You need the PSU fan to suck air out, not mix it in the case.

COMPLETELY BOGUS IDEA.  Go buy yourself a decent PSU if your current one is no good.

P.S. If your car aircon is not good enough, you don't get a can opener to take the roof off and then add extra fans.


----------



## keakar (Sep 18, 2007)

the whole idea was because the 120mm fans blows its ass off and the air hits a wall so to speak in the circuit board the just kinda drifts out the back without much cfms force at all.

so you have a fan that cant force the air into the psu so its just spinning but IMO hardly pushing any air through the psu.

even the single rear fan types have very few air openings IMO so the airflow is restricted for them as well.

if air moved through the psu at the same rate of cfms as if the fan were a case fan wouldnt it be better?


----------



## keakar (Sep 18, 2007)

bump


----------



## Namslas90 (Sep 18, 2007)

They make PSU's with dual fans, and you can always add a fan or put in better fans.  You gotta know what your doing though,  make sure it's fully discharged, and be carefull not to touch anything other than fans, fan wires etc.  

Still don't recommend it, just buy a Quality PSU with a higher rating than you need and it will run cooler, because it won't have to work as hard to power your computer.


----------



## panchoman (Sep 18, 2007)

lemonadesoda said:


> Dont do it. The thick case of the PSU does 2 things:
> 
> 1./ Creates an earthed cage around the PSU components. This stops A LOT of e-noise.
> 
> ...



ditto, while you probably can, very very bad idea. the cover actually keeps the heat inside the psu and take it out of the case, exposing the psu heat to the system, that too with a fan to take out all the heat and through it at your system is not a good idea. a single 80mm fan will cool the psu the best.


----------



## keakar (Sep 18, 2007)

well what if i replaced the back panel facing the drive bays with an open grill like you see on the rear of most 120mm fan psu? in a psu with a rear exhaust fan it could then draw air straight through it with no restrictions. i dont really care how its done i just wanted to figure a way to increase the psu airflow.

i even thought of cutting a hole to mount a case fan to push air through it but the 120mm fan blocks it.

the thing is that most quiet psu run hot, not too hot but they do run hot all the time so i want to move more air through it without increasing the noise.


----------



## kwchang007 (Sep 18, 2007)

DaMulta said:


> You can, just don't touch anything in there. It hurts really really bad. You just have to trust me on that one.



Oh god that feels weird.  I've done it once....thank god I only had one hand near it.


----------



## panchoman (Sep 18, 2007)

how do you guys get electrocuted by a 500W+ psu and live to tell the tale? anyway, if you want more psu airflow, just cut some more fan holes and add fans. you want the psu heat to not enter the system, psu's run at around 40C on average. and you dont want to dump that heat onto your cpu/vid card. the job of the cover is to protect you and also to contain the heat untill it is removed from the system.


----------



## kwchang007 (Sep 18, 2007)

panchoman said:


> how do you guys get electrocuted by a 500W+ psu and live to tell the tale? anyway, if you want more psu airflow, just cut some more fan holes and add fans. you want the psu heat to not enter the system, psu's run at around 40C on average. and you dont want to dump that heat onto your cpu/vid card. the job of the cover is to protect you and also to contain the heat untill it is removed from the system.



It's not that hard to survive an electrocution.  And at any rate, mine was from like a 100 W psu.  The psu was open (checking the fuse) so I put the new fuse in, plugged it in and powered up....it worked, then I unplugged from the wall and the mobo, picked it up with one hand, and then dropped it as it shocked me.  The flow of electricity never crossed my heart or brain...the important parts.  

As far as this psu out of the casing....really don't do it man, casing is important, because capacitors can hold their charge for a while and you don't want to have to wait a few hours to make sure it drains and such.  Just mount the PSU where it's supposed to be.


----------



## keakar (Sep 18, 2007)

im an old ac repairman.

at least once a month i got zapped, mostly from 220v which strange as it sounds is safer than 110v. the 220v hits you like a punch and knocks you off it. 110v grabs you and holds on, thats the one that kills people.

capacitors are like being tasered or cattle prod.

as far as cutting hole, the 120mm fan is like 3/8" from touching heat sinks and anything below it is blocked by capacitors n stuff. if i remove it the air will go over the psu but not onto it so no cooling.

there are very few straight through fan designs anymore and the few i see are noisy as hell.


----------



## erocker (Sep 19, 2007)

A good PSU wouldn't get hot enough to bother anyways...


----------



## Disparia (Sep 19, 2007)

You just need a large PSU shell 

Unfortunately the cases that fit them are pretty rare...


----------



## Namslas90 (Sep 19, 2007)

keakar said:


> im an old ac repairman.
> 
> at least once a month i got zapped, mostly from 220v which strange as it sounds is safer than 110v. the 220v hits you like a punch and knocks you off it. 110v grabs you and holds on, thats the one that kills people..



That's not rue everywhere, In Europe I watched a stereo timer grab a guys thumb and I had to kick him off of it.  It burned a hole about 1/4 inch wide down to his thumb bone. It depends on the amperage and the phase of the electicity.



keakar said:


> capacitors are like being tasered or cattle prod..



Cattle prods have rather large capacitors in them.

It's not the PSU itself that does the damage but the capacitors in them that will hold a strong charge in them kind of like a CRT does.  In electronics class in colege we shorted a large old cap with a wire from a distance and blew a hole in the ground about 3 feet wide and 3 feet deep.  It was our Proffessors last year, he retired after that class.


----------



## Frick (Sep 19, 2007)

What you can do to improve airflow is just to put a 80/92mm-fan on the front of it, so it blows backwards. I did that to an old psu I had, and it actually improved things.


----------



## ex_reven (Sep 19, 2007)

Its the amps that do the damage, not the voltage.

You can get hit by 200,000 volts and not die if the amperage was low enough.
Too many amps causes your heart either to stop or to fall out of sync, which is why you see them using shock paddles (defribulators) in medical movies/tv shows like house. Defribulator paddles can not start a stopped heart, but they can shock a heart that is running out of sync back into sync.


----------



## Wile E (Sep 19, 2007)

ex_reven said:


> Its the amps that do the damage, not the voltage.
> 
> You can get hit by 200,000 volts and not die if the amperage was low enough.
> Too many amps causes your heart either to stop or to fall out of sync, which is why you see them using shock paddles (defribulators) in medical movies/tv shows like house. Defribulator paddles can not start a stopped heart, but they can shock a heart that is running out of sync back into sync.


And to add to the fun facts, it can take as little as .1A going across your chest to kill you. Note that the number is one-tenth, not one.


----------



## ex_reven (Sep 19, 2007)

I think its also important to note that no PSU can be opened without voiding its warranty.


----------



## tkpenalty (Sep 19, 2007)

yep... 1A = DEATH. You would be incinerated and die. Removing the PSU from the casing is SUICIDE. its extremely dangerous, dont try it. You guys are very naive to think that it will hurt. You will DIE okay? End of story, even if its not plugged in, the discharge from the PSU's capacitors is enough to severely damage your body.

DONT DO IT. A TPU user dying is seriously tragic.

EDIT: You can remove it if you do a full discharge though.... but i wouldnt bother, you have to leave PSU out for 48 hours+. UNPLUGGED.


----------



## AsRock (Sep 19, 2007)

If this is what your using Geez give that comp a good PSU dammit
http://www.newegg.com/Product/Product.aspx?Item=N82E16817163013&Tpk=ultra+400w


----------



## DaMulta (Sep 19, 2007)

tkpenalty said:


> yep... 1A = DEATH. You would be incinerated and die. Removing the PSU from the casing is SUICIDE. its extremely dangerous, dont try it. You guys are very naive to think that it will hurt. You will DIE okay? End of story, even if its not plugged in, the discharge from the PSU's capacitors is enough to severely damage your body.
> 
> DONT DO IT. A TPU user dying is seriously tragic.
> 
> EDIT: You can remove it if you do a full discharge though.... but i wouldnt bother, you have to leave PSU out for 48 hours+. UNPLUGGED.



Dude I was messing around with a PSU that had sit for about a year unplugged when I got shocked the last time. I was stealing it's fans when my screw driver slipped.:shadedshu


----------



## HAL7000 (Sep 19, 2007)

The power supply is in a steel box for a good reason, so in comparison, why not remove the main breaker box in a house ......just the point....*insane*!

This is a good read and reminder for the wise to remain wise.....

http://physics.ohio-state.edu/~p616/safety/fatal_current.html


----------



## Frick (Sep 19, 2007)

tkpenalty said:


> yep... 1A = DEATH. You would be incinerated and die. Removing the PSU from the casing is SUICIDE. its extremely dangerous, dont try it. You guys are very naive to think that it will hurt. You will DIE okay? End of story, even if its not plugged in, the discharge from the PSU's capacitors is enough to severely damage your body.
> 
> DONT DO IT. A TPU user dying is seriously tragic.
> 
> EDIT: You can remove it if you do a full discharge though.... but i wouldnt bother, you have to leave PSU out for 48 hours+. UNPLUGGED.



I had my PSU open for a couple of months with a 140mm fan on top of it. It was on top of my computer and I got shocked a couple of times (accidentely touched where the power comes in a few times), but I didn't die. I think you exaggerate things. It's still dangerous though..

EDIT: Of course you can die, but not from just pointing at the PSU with a wooden stick.


----------



## keakar (Sep 19, 2007)

Frick said:


> What you can do to improve airflow is just to put a 80/92mm-fan on the front of it, so it blows backwards. I did that to an old psu I had, and it actually improved things.



are you talking about a push in pull out fan system or do you mean you put a push in push in fan system?


----------



## keakar (Sep 19, 2007)

AsRock said:


> If this is what your using Geez give that comp a good PSU dammit
> http://www.newegg.com/Product/Product.aspx?Item=N82E16817163013&Tpk=ultra+400w



thats a piece of crap.

mine is no high end gem itself but at the time it was and still is a very stable good quality psu. although this is the "V" series and mine is the "true power" series they are the same. the "v" series replaced the "true power" series a while back.

http://www.ultraproducts.com/product_details.php?cPath=59&pPath=369&productID=370


----------



## keakar (Sep 19, 2007)

DaMulta said:


> Dude I was messing around with a PSU that had sit for about a year unplugged when I got shocked the last time. I was stealing it's fans when my screw driver slipped.:shadedshu



you must have had it running when you took it out. the juice drains out slowly by bleeding back through the devices hooked to it that stay powered up, usually just the motherboard. but it still should have dissipated by that amount of time unless you have something wrong with that psu, a month maybe but a year? i think it was static discharge.

it can be trapped like a battery if it has juice in it and is not plugged into anything. i always recommend turning off and unplugging main power cord then waiting overnight before you unhook it.

you can safely remove stored up juice from the psu by plugging it to any motherboard and in around 12-14 hours it will be drained.


----------



## keakar (Sep 19, 2007)

Frick said:


> I had my PSU open for a couple of months with a 140mm fan on top of it. It was on top of my computer and I got shocked a couple of times (accidentely touched where the power comes in a few times), but I didn't die. I think you exaggerate things. It's still dangerous though..
> 
> EDIT: Of course you can die, but not from just pointing at the PSU with a wooden stick.



well i was talking about keeping the psu inside the case. i could leave the psu case open only because i have worked with "live" power all my life so after being shocked over a hundred times and feel i can work around it safely. i once lost the use of my arm for 2 days and it was numb and hurt like hell all by a slight touch to a live terminal. what makes the difference on living and dying is how well you are grounded. the better you are grounded the more amps you get and the harder it hits you.


----------



## Frick (Sep 20, 2007)

keakar said:


> are you talking about a push in pull out fan system or do you mean you put a push in push in fan system?



Push in push out, I think.. Push in via the front, push out through the back. But that was with a 6 year old 350W PSU that sucked when it was new, so anything was better than the orignial cooling. It was the same PSU I had opened with the 140mm fan on top it. It didn't like my x1950 pro very much.. 

Also, pfha.. Grounding are for cowards. 

Seriously though, it's not, but.. If you're careful most things are cool. I mean, a PSU isn't that big, so it's easy to see everything (not to mention if something looks bad) and therefore do everything in a somewhat safe way. I assume it's harder when it's something big and there's a lot of people involved..


----------



## spud107 (Sep 20, 2007)

check if the psu's fan is linked to a thermal control,  could just change it to a manual one.


----------



## niko084 (Sep 20, 2007)

You can, but don't.... The directed airflow is much more efficient at cooling then just open air because it passes over everything it needs to cool. A larger casing would be good with larger fans, but it does need to be directed...

Also the whole shielding part does play a large roll and parts in a psu can be pretty dangerous if you touch the wrong part, even if its unplugged.


----------



## Cuzza (Sep 20, 2007)

ex_reven said:


> Its the amps that do the damage, not the voltage.
> 
> You can get hit by 200,000 volts and not die if the amperage was low enough.
> Too many amps causes your heart either to stop or to fall out of sync, which is why you see them using shock paddles (defribulators) in medical movies/tv shows like house. Defribulator paddles can not start a stopped heart, but they can shock a heart that is running out of sync back into sync.




You'd have to be a highly resistive person to not get death amps from 200,000 volts though right? I stuck a wire in a wall socket when I was a kid, got a mean jolt outta that. 

I also had a physics teacher who used to charge up caps and leave them lying around the lab when the class came in, then he'd have a great laugh when some unfortunate bastard picked the thing up. What a funny guy.


----------



## Carcenomy (Sep 20, 2007)

I do find it moderately entertaining, all this talk about how important the body of the PSU is. It's not thicker - most power supplies I see either use thick steel to mimic heavier components, or use the same SECC steel as the chassis it came in. If the casing was so important, how do people get on with windowed power supplies, acrylic covers, and so on?

Yes, you can mount it outside its casing - but it needs to be pretty exceptional circumstances to warrant it, you need to position it VERY carefully, do NOT lose any of the insulation that fits between the PSU's PCB and body, and don't handle it straight after it's been powered up - leave it to discharge for a while first. Putting it under some load with the juice off can help.

To illustrate this, I've relocated a power supply PCB recently. The machine was an old slot-load Pentium III, we're dropping a slocket mounted 933 in it to replace the original 533, and equipping it with a crazy air cooling system of my design. But the PSU was mounted directly over the CPU, and was not only an aesthetic bane, but a performance issue. So now it's mounted in the lower front, and has its own venting system to the bottom of the case. Hasn't shocked anyone, performs fine, looks good.

I guess the moral is - if you want to do it, it's feasible, but take LOTS of care, and if you don't feel up to it, stop considering it altogether.


----------



## Wile E (Sep 21, 2007)

Cuzza said:


> You'd have to be a highly resistive person to not get death amps from 200,000 volts though right?


No. Voltage doesn't kill at all. Amperage is what kills.


----------



## kwchang007 (Sep 21, 2007)

Wile E said:


> No. Voltage doesn't kill at all. Amperage is what kills.



Amps kill....volts hurt, and volts also are the things that paralyze you.


----------



## Cuzza (Sep 21, 2007)

Wile E said:


> No. Voltage doesn't kill at all. Amperage is what kills.



I know that. my point is it takes quite a bit of resistance to stop a serious current flowing across 200,000 volts. like the guy on this page http://physics.ohio-state.edu/~p616/safety/fatal_current.html says, skin resistance can be upwards of 500,000 ohms. at 200,000 volts that still gives you 0.4 amps. That's above the death zone but still pretty bad.


----------



## kwchang007 (Sep 21, 2007)

Cuzza said:


> I know that. my point is it takes quite a bit of resistance to stop a serious current flowing across 200,000 volts. like the guy on this page http://physics.ohio-state.edu/~p616/safety/fatal_current.html says, skin resistance can be upwards of 500,000 ohms. at 200,000 volts that still gives you 0.4 amps. That's above the death zone but still pretty bad.



That's under the impression that your running 1.0 amps at 200,000 volts.  Then you have 200,000 watts, which divided by 500,000 ohms will give you 0.4 amps.  If you have say..0.1 amps through 200,000 volts, you'd have 20,000 watts divided by 500,000 (let me get the calculator, lol) .04 amps.  So that's defiantly under...see it all depends on the amps.  Oh and I never knew that above a certain point you're safe...huh.  Anyways, best way to keep yourself safe is when working on electric things (opening a psu) DON'T ground yourself, and try to use one hand.


----------



## Cuzza (Sep 21, 2007)

I would love to see in a movie or something, maybe MacGyver, someone intentially electrocute himself to get out of a tight situation and knowing the current would be above the death amps range. And then make a bomb out of string and chewing gum. Go MacGyver.


----------



## thebeephaha (Sep 22, 2007)

DaMulta said:


> You can, just don't touch anything in there. It hurts really really bad. You just have to trust me on that one.



Hahaha, ooooo. Been there done that, it hurts about as much as if you've ever tried to take apart a disposable camera with flash and bumped the cap in there after its just been charged......


----------



## keakar (Sep 22, 2007)

kwchang007 said:


> That's under the impression that your running 1.0 amps at 200,000 volts.  Then you have 200,000 watts, which divided by 500,000 ohms will give you 0.4 amps.  If you have say..0.1 amps through 200,000 volts, you'd have 20,000 watts divided by 500,000 (let me get the calculator, lol) .04 amps.  So that's defiantly under...see it all depends on the amps.  Oh and I never knew that above a certain point you're safe...huh.  Anyways, best way to keep yourself safe is when working on electric things (opening a psu) DON'T ground yourself, and try to use one hand.




........................... stop all the damn math, your making my head hurt lol.

i think the list goes like this:

very painfull

original crispy

extra crispy

and burnt


----------

