Now that makes sense :p Just post pics for us when it's done...

DigitalChaos has a good point as I also had an Antec 400 watt PSU but like the PC power & cooling he has it was far too cluttered internally to use for my project design / solution. The only issue with using the heatsinks that are already in the PSU is often they are live mains voltage (or at least one of them is). This would have the undesired effect of making the coolant live if a metal block was attached to it, (causing an earth trip or fuse to blow in UK mains systems.

I was thinking about a PC power and cooling 600watt or 650watt for future water cooling. Can't remember the model now but it's a double sized unit. not sure if it's server / duel CPU only. anyone have one of these?

hrm... good point about the heatsinks being live... i would imagine i could just connect one of those to ground and see what happens...

most of the mosfets apear to have a thermal pad between them and the heatsink which would stop the heatsink from being live...

also, i could just attach my water blocks with a big thermal pad to prevent electricity from flowing.

I'd favour getting a Mulitimeter, (and someone that has the know-how to use it if you don't) to check the sinks for "liveness" rather than deliberately shorting it out.

The fact the mosfets have mica shims doesn't mean the sink is not live. The mosfets in the enermax were all shimmed but the sinks were live. I could find no definite reason why they needed to be live. Now the sinks are not there, and the block in the PSU is earthed with the mosfets attached to it also fully isolated with the same mica shims without any obvious downside. more about this in the PSU cooling build on my site.

I gave a thought to this heatsink problem, and the only reason i see for them to be live is EMI noise reduction (unless they're actually connected to the rest of the circuit).
Put 2 opposing sinewave signals in 2 opposing blocks of metal - in the middle you've got a flat line.
In this case maybe the sinks are live to compensate the unavoidable mains noise you've got on mosfets output.
The only way to work this out is with a good oscilloscope.

no, the reason they are live, is the design of most mosfets... the metal plate that attaches to the heatsink is live.

Wow never saw this kind of mosfet regulator.... usually the backplate is connected to GND meaning it's at 0V. Like BR said pick up a multimeter and tell us what's going on
:cool:

gmat

I think it must be something like that as there has to be a reason. Like you say the metal back part of the Mosfets on my PSU is now & was before the water-cooling at 0v, it's the heatsink itself that was live mains voltage. The sink also wasn't being used as a bridge joining two parts of the PCB together either, as I checked for this.

The mica shims prevented the back part of the mosfet touching the sink directly, (as far as electrical conductivity is concerned),

I don't pretend to understand fully how a PSU works, but the water block is now earthed and the mosfets mounted in the same way with the same mica shims. It appears to work ok without the original heatsinks "liveness". Like you say a scope and someone that knows how to use it is what's really required :)

In some PSUs the Sink is used as a bridge between 2 Points of the PCB... I modified already 2 Enermax 550W where I had to soldier a bypass under the PCB...

But other than that reason there is no sense in live sinks...




I modified many Enermax PSU...

Here are some pics:

http://www.cooling-solutions.de/foru...axwakue2-1.jpg

http://www.cooling-solutions.de/foru...axwakue2-5.jpg

Heavy modified watercooled Enermax 550W:

http://www.cooling-solutions.de/foru...axwakue3-1.jpg

Another One:

http://www.cooling-solutions.de/foru...axwakue3-4.jpg

Nice!!!!!:)

ct100

Interesting, as with my 550watt the power rail origin was the same point, so the bridging it would not have made any difference.

I notice that you have a copper "Cover" near that coil in mine that gets hot. Is it in contact with the coil?, I was intending to do something similar but wasn't sure if it might short something.

It can be seen in this image, it's the coil shown by the shorter Pink arrow, (click for large image).

http://www.zerofanzone.co.uk/picture...rmax1small.jpg

If this is possible I could easily run a copper plate to it from the side of the waterblock shown here.

http://www.zerofanzone.co.uk/picture...max3asmall.jpg

Enermax PSU's are very different, even if they have the same model no... so its possible you have another version of this PSU...

2 of my Enermax needed this bypass... without it, they could not provide 5V Standby Voltage...


This copper "Cover" is made from a 1,2mm thick copper plate, and does his job very good in cooling the Coil... no more 70°C+ now

I used AS2 under this "Cover" to make better contact to the Coil

http://www.cooling-solutions.de/foru...axwakue3-5.jpg

Does this not affect the coil. I would have though that it is a coil for a reason, so by connecting it with a copper plate and artic silver will make it less of a coil if you get my meaning, sort of shorting out one part to another.

It does not short the coil!

The copper wires of the coil arent pure copper... they have a very thin layer of shellac arount the copper... so they arent conductive at the surface...

AS2 isn't conductive, too...

so you dont have to worry about shorting something by covering the coil with a copper plate

The layer on the coil is a thin varnish. Any scratch on it and the copper will be exposed. For safety reasons i'd put an extra mica shim between the coil and the copper plate.....

well i took a volt meter to this thing.... and this is what i got.

the heatsink on the left has no voltage with the casing (ground)

for the heatsink on the right i got 120AC or 55DC with the negative lead on the heatsink and the positive lead on casing (ground)

these readings are for both the aluminum and copper sides of each set of heatsinks

now this little heatsink set scares me... i got this reading on both the copper and aluminum

750AC or 350DC with the positive lead on the heatsink and the negative lead on the casing (ground)

soooo.... looking at the way things are in there... im thinking about putting a quiet 80mm in there as a replacement.. and then put a hole in the top for a 120 or 92 mm to pull more air out.

I dare you to touch it ;)

Thats 2 fans, and 1 more than stock :rolleyes:
You just lose the purpose of modding that PSU. (reading your original post again...) If you want to get rid of noise, the solution is clearly not adding more fans...
BTW the readings you want are the AC ones. If the heatsink is acting like a bridge just disconnect it and replace it with a wire on the opposite side.
Again i doubt that copper part IS a heatsink. Looks REALLY like a EMI shield. It's hot because of magneto-resistive effects produced by the nearby coil.
And yeah there are some very high voltage parts in a PSU. Thats usually written on a big sticker :D (i know i know, us geeks just pop it open disregarding red & yellow hazard signs...)

a 55cfm 23dba 120mm and a 30cfm 22dba 80mm fan is much quieter than a 46dba 80mm fan ;)

exactly my thoughts.... the stock 80mm is VERY loud

no fan is much quieter than any fan ;)

but the sound my $200 psu makes when you short out the heatsinks is byfar the loudest =)

well the copper part was cut to make little fins... also the other 2 main aluminum heatsinks also have this same copper finned heatsink on the opposite sides of their chips....



also... there is a series of air holes cut out of the casing next to this little heatsink

maybe its a dual purpose heatsink/emi shield



wouldnt it be cool to have a pcp&c engineer in here? he could tell us exactly what is and what isnt safe to be doing to it.... and exactly why some heatsinks are live and some arent.

If you happen to know an electrical engineer who's got access to a lab or at least an oscillo, bring the PSU to him he may tell you whats up :p PSU's are very easy to reverse engineer, they're all made the same so differences are quickly noticeable.

I doubt it, probably just tell you removing the cover would void the warranty, and be horrified at the idea of water-cooling one :p

iv been wanting to wc my psu, its only got 1 line of mosfets, and i havent got around to design my wb, but its gonna look similar to the heatsink, the heatsink is a big T, but im only worried about the conductivity, i was thinkinga bout getting non conductive aluminum...