RMA'd AX650 also has issues. Can't isolate anything other than PSU issue.

[MadMonocle]

Hi guys, I'm asking for help here because I've already tried google and Corsair RMA.

 

I have an AX650 PSU and started having issues with my PC not powering up when pressing the power button. The power supply 'clicks', all the fans start spinning up and after 0.5 seconds it clicks again and the fans stop. The power button's LED fails to turn on. All the USB power works though (my external spins up). The only way to get the PC on is to try a combination of resetting the CMOS button on the mobo, or switching the power supply off and on, and then it only works randomly after 6 or 7 tries. When it does finally work, the power LED turns on. No problems when the PC is actually on. Everytime I start the PC from a cold boot it has this problem, although randomly, and only when the shut off is clean, it will power up just fine. But not every time!

 

So I swapped the PSU with an Antec one I had. NO PROBLEMS. Powered on just fine. So I sent in the AX650 for RMA. I got the new unit a few weeks later, wired it up with the new cables and everything. SAME EXACT ISSUE! Swapped it out for the Antec again: NO PROBLEMS!

 

So my question is: why is the PSU, which is universally praised for it's high quality, failing to work properly in my build. It's a modern build, and there have been overclocks or mods to the BIOS or anything.

 

Very irritated because I specifically sprung for the AX650 because of it's supposed high quality. It can't be a dud either because I've already RMA'd and the new one failed! There can't be problems with the power switch because the Antec PSU worked flawlessly. If it's the PSU, why isn't it considered bad by anyone? Thank you so much for any help!

[jonnyguru]

So you tried an Antec in place of the Corsair in your build, but did you try the Corsair in another PC?

[MadMonocle]

I have not, as unfortunately I don't have access to another PC to dismantle. I'll see if I can do that later. Right now I'm looking for theories or possible solutions.

[jonnyguru]

My theory is a potential PSU good signal timing compatibility issue between the motherboard and the PSU. You can try the Corsair in another PC or use a PSU tester with an LCD display on it like this one: http://www.newegg.com/Product/Product.aspx?Item=N82E16899261023

 

And see what the difference in PG Signal is between the two units.

 

That tool should be in every PC builder's toolkit. I use mine all the time.

[MadMonocle]

Thanks for this new information and that link! I'll look into that signal issue.

 

If there is a PSU issue, do you think Corsair would accept an RMA and give me a different unit? I wouldn't necessarily demand a huge upgrade, just a PSU that is compatible, fully modular and not a downgrade in wattage.

[jonnyguru]

I just don't know. I work for Corsair as a contractor and don't know the policies on those things. Your best bet is to contact support on that one.

[Rockzz]

Hi,

 

Within people having a defective part of this product, it seems we are many to have the same exact issue (I just listed within the forums first page, there's likely more occurences in further ones):

- http://forum.corsair.com/forums/showthread.php?t=127888

- http://forum.corsair.com/forums/showthread.php?t=118702

- http://forum.corsair.com/forums/showthread.php?t=127644

 

I suggest any of us create a thread dedicated to this very specific issue, to show how many ones are affected, to compare hardware (mainboards).

 

From here, I use an old but rock solid motherboard, Gigabyte GA-EP45-DS3P with an Intel Core 2 Duo E8400. Nothing is overclocked, all worked well with the same hardware for 1.5 years approximatively, then the problem started. I questionned myself about my flat power supply, or the wall outlet having too many equipments connected to it, but no in the end: nothing changed in my install.

[Rockzz]

Main thread with RMA expectations: http://forum.corsair.com/forums/showpost.php?p=704689&postcount=1

[MadMonocle]

Update: So I just finished building an AMD FM2+ MicroATX (Gigabyte A88X-D3H mobo) build, and decided to test the dud AX650 PSU with it. It works wonderfully! No issues!

 

Perhaps the AX650 is incompatible with Haswell or Intel. I'm going to buy a new one, but I'm still curious what the source problem was.

[jonnyguru]

Shouldn't have issues with Haswell. The big difference with Haswell and why there's a "qualified PSU" list is because of the sleep state. As long as the PSU uses DC to DC for the non-primary rails, and the AX does, there should be no issue with the C6/C7 sleep states.

 

That said, could be a compatibility issue with the particular motherboard.