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HX850W and Cosmos S power switch problem.


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In order to draw attention to this issue I have started another thread.


Here is the thread made by someone else who is having exactly the same problem as me:




In order for the cosmos S case to function properly it requires a power connection when the motherboard is powered down. The reason for this is there is a touch sensitive switch on the front of the case that cannot function without it. Coolermaster chose the obvious route of powering it directly from the power supplies "always on" lines using an adapter shown below:




This adapter connects between the 24pin on the power supply and the 24pin on the motherboard. The front panel then has a standard atx switch cable which plugs into the motherboard to turn the computer on and off.


This system worked perfectly fine on my previous Hyper 550w power supply, I also tested it with a rubbish no brand psu and it worked with that too.


The problem arose when I upgraded my psu to the corsair hx850w in anticipation of getting some more power hungry hardware. When I plug in the hx850 in the exact same configuration as before, if the power button is pressed the computer starts for around 5 seconds then powers back down immediately before it even posts.


If I unplug the atx switch from the motherboard and use the motherboards on board switch it works fine, if I don't unplug the atx switch when using the on board switch the computer powers down as well just as before.


Here's the interesting bit. If I unplug the adapter(which provides power to the front panel) and plug it into an external power supply, leaving the corsair to give power to the rest of the computer then everything works fine. The power button on the case works flawlessly and I can boot into an OS and stay there indefinitely.


It seems to me that there is a problem with the power supplies output to the front panel when the computer is turned on if not always.


Picture of configuration that does not work:



Picture of configuration that does work with rubbish power supply plugged in to provide power to front panel:



This looks to me like a sure problem with the power supply and hope you guys at corsair can come up with a solution.


I would be interesting to know if people with different wattage power supplies from corsair are having the same problem with this case or whether it is just this particular model which is errant.

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I only have 7 days to return the psu to the manufacture unless you guys classify the part as faulty. Could I get an answer soon please or at least some acknowledgment you are looking into it? I don't want to have to rma this thing all the way back to the states from the uk.
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I just did some voltage tests.


Purple-Gnd(when off): 5v

Purple-Gnd(when on): 5v

Yellow-Gnd(when off): 2v!!!!!!!

Yellow-Gnd(when on): 12v


As you can see yellow to ground when the psu is switched off is reading 2v! It reads 0v on all my other psus. This seems like the most obvious cause of the malfunction to me, would you agree?


I hope this isn't a model wide issue or corsair have a problem on their hands.


Is it safe to RMA this for another hx850w and expect that then new one will work ok? Or should I choose a different wattage that doesn't have the problem? Or is this a corsair wide problem? Will I have to go with a different brand?

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That's odd, i didn't think it would happen to anyone else. To be honest i'm not sure if anyone is at fault here. The Corsair PSUs work with all other cases and the Cosmos cases work with all other PSUs.


I think it would be best if Corsair and Coolermaster worked together to find out what's causing this anomaly. Untill then though, you'll have to ditch either the case or the PSU.

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  • Corsair Employees
We have verified that this setup works. If you want, we can certainly get this PSU replaced for you (just follow the link on my signature). However, we would suggest you to contact your case manufacturer to see if they have a different revision of this soft touch switch. If the PSU works fine without the switch connected, then the PSU is not bad at all at least from our stand point.
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We have verified that this setup works. If you want, we can certainly get this PSU replaced for you (just follow the link on my signature). However, we would suggest you to contact your case manufacturer to see if they have a different revision of this soft touch switch. If the PSU works fine without the switch connected, then the PSU is not bad at all at least from our stand point.


What about the bogus voltage I'm getting on the 12v rail when the psu is off?

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  • 4 weeks later...

Got the same problem as the OP but with the following hardware on a customers PC.


Intel I7 920

Corsair TR3X6G1600C9 6Gb

Palit GTX 285 1Gb

Samsung HD103UI 1Tb Hdd

Pioneer DVR-216BK dvd

Cosmos S case

800w Gigabyte Odin PSU (manufactured by FSP)

Windows Vista64 SP2.

So not restricted to Corsair PSUs.

Would seem it is an issue with the Cosmos S touch sensitive switch and the way it works.

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  • 4 months later...

I have the same issue, with a TX750. this is my brothers rig and what a nightmare we've had trying to figure out what the deal is.


after alot of reading other forums, this seems to be happening to alot of people, all with different PSUs. Ive tried the same rig with an older Atrix PSU and have the same problem as with the TX.


heres the interesting thing. if you start the PC, then when everythings on, in the first 4 seconds, remove the powerSW front panel lead from the mobo, she wont turn off and runs fine. it seems that for some reason the power switch on the cosmos is in permanent short. now some are saying replace the I/O panel on the case, those who have done that have had no joy, still having the issue. this leads me to think that its some kind of compatibility issue with the motherboard.


We're using a brand new Asus P5N-D... seems to me so far that Im seeing this problem almost exclusively with Asus mobo's.


I dont think its your psu.

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to be quite honest, Ive been disappointed in the build quality of the Cosmos S. the rear panel flexes a lot when you push the motherboard port plate in, so much so you need to hold it on both sides or itll bend out of shape.


the drive 'quick' releases are quite handy, but as they only fit on one side they leave the optical drives and hard drive cradle quite rattly. The fan mounts on the front dont do up tightly causing more noise as well.


all things considered, Im not surprised that so many people have so many issues with the front IO panel. Its a gimmick, nothing more.. after all, who needs a touch sensitive switch anyway? Sure its a large case, with plenty of room for rads and other cooling pokery, but so are alot of others for alot less money!


do yourselves a favour, RMA the case and buy something better, which would be most things. Thats what we'll be doing with this one!

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  • 8 months later...



I'm running into the same problem - however, I had a HX850W that I swear was working just fine with my Cosmos S for about a week before it went dead. I only began experiencing the problem when I got the replacement. I figured I had another defective unit when it wouldn't stay off, and received my then third HX850W which is having the same problem as the second.


I guess my question then is: Does anyone with a Cosmos S NOT have this problem? I don't know if I ought just keep replacing or not until I get another working PSU :| Am assuming it's per the 2v on wire where there should be none... which would make it Corsair's bad and not CM's, right?

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Did your replacement HX850W resolve the issue you were having with the Cosmos S?




I now think that the problem I had was a combination of two factors:


1. The psu appeared to be outputting the wrong voltage on the always on 12v pin as explained in my thread. You should check yours with a voltmeter to look for the same problem.


2. The power adapter on the cosmos s (which sits betwen psu and mobo) doesn't seem to make a good physical connection with either the mobo or the psu.



After replacing my psu with a new hx850 the problem seemed to go away to a degree, the replacment psu had all the correct voltages, I could now boot with the front panel plugged in but my pc would power of randomly while running.


I found that the random power off problem was to do with the cosmos s adapter not making a good connection with one of the mobo or psu. This meant that if I knocked my pc ever so slightly and the adpater moved then it would power down.


After cutting a cable managment hole, which can be seen in the pictures below, and bending the adapter round and through it this problem has gone. I guess the act of bending it round has forced the metal contacts better together.






Of course you could make your own cosmos s adapter by using good quality atx extension and splicing the connector from the old adapter onto it. This would also likely fix the problem. I may do this in the future but havent got round to it yet.


Out of interest, before you send your psu back for a replacement could you try putting pressure on the adapter while the pc boots to see if it fixes the problem?

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Wow, great job alphafish - you were right on the money! When pulling the blue/yellow power button cable forward towards the front of the case, the issue goes away! Yaaay, so glad I can enjoy my HX850 now :)


BTW: Is the 1.3v or so on the yellow 12v wires of ATX power cable while unit is off considered within spec? Should I be concerned or happy that it's working?

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