Very bad experience with an Antec SU-380, suggestions needed

[curtisfong]

I picked up a NSK2400 case to replace a NSK3300, and the included power supply buzzed horribly. I sent it to Antec for an RMA and received an updated unit, with very short cables (12" ATX) along the lines of the oem Seasonic 300w unit in the 3300. The original supply had normal length (24" ATX) cables.

Unfortunately this one buzzed just as badly, especially at low load. Antec did not reply to my emails, so I opened up the power supply and liberally applied cyanoacrylate adhesive to the coils, and let it cure for 12 hours. This dampened the sound somewhat, but it's still there (and very annoying). Replacing the stock ADDA fan for a made-in-Japan panaflo did prove beneficial.

To make matters worse, the power supply will not fully power down the machine. The computer shuts down, but the fans are still running.

Does anyone have any suggestions before I replace the supply? I guess I can live with the odd shutdown behavior, but I can't live with the coil whine for much longer!

[jaganath]

Some PSU's are just cr@p. Send it to the great junkyard in the sky.

[KorruptioN]

Full specifications of the computer in question would help...

[Brian]

My Antec TruePower 500 buzzes horribly, even in Standby mode. Unacceptable, even to mainstream computer users. While researching the matter, I came to the conclusion that a large percentage of Antec PSUs buzz (based on reports from other SPCRers). So, send it back and get something that's not an Antec.

[curtisfong]

I have a 7900gt, which draws about 70w or so (540 core 1600 ram, 1.4v); 2.5ghz a64 w/ 512k cache, 1.35v; 1 HD; one optical; 2gb of ram; audigy2.

I will probably use the oem Seasonic SS-300SFD - 80 Plus from my nsk3300 case; it's very efficient and should supply enough current on the 12v outputs for my system. Hopefully Antec did not adulterate it substantially.

It's too bad I basically have to junk a new PSU. The SU-380 is based on a Seasonic super silencer; Antec must specify cheaper parts to save a few dollars.

Most Antecs are oem Seasonics or CWTs actually; it's a shame that they do not perform like them.

[lutorm]

To make matters worse, the power supply will not fully power down the machine. The computer shuts down, but the fans are still running.

Did you mean standby, or do the fans run when the computer is completely off? If it's standby, it usually means the computer has gone to S1 instead of S3 which can happen because either S1 is set in BIOS, or a device is preventing the machine from going to S3. Look in the device manager and uncheck any "Allow this device to bring the computer out of standby" under power consumption from all devices (typically USB mice/keyboards, etc).

If the fans don't even turn off when the computer is "off", that's seriously weird. I'd agree that you should throw it far, far, away in that case...

[curtisfong]

Did you mean standby, or do the fans run when the computer is completely off?

The latter. The machine was working perfectly with a FSP 400 Green PS, which I gave away with the NSK3300 case. The bios hasn't changed, but I will poke around anyway.

[zepper]

This seems to happen only with some mobos and not all. I was wondering how isolated the +12 rails in the SU-380 PSUs are. I only use the 12V1 to power my CPU which is entirely isolated from 12V2 and I'm having no buzz problem from my SU-380. Now if others are also using the PCI-X connector, could that somehow get connected to the ATX/periph rail (12V2) internally to cause the buzz. Most split rail PSUs don't really have well isolated rails and shouldn't have such problems.
. As far as I'm concerned, the SU-380 is a quality, Seasonic-built psu (identical inside to ones in the Super Silencer series) and have been recommending them highly. If your mobo isn't keeping the +12 from the different rails isolated internally, then it's not the PSU's fault - talk to your mobo maker. Seems like Asus is one of the big common links in this problem. I'm running an Abit, but as I said I'm not using the 12V1 for anything other than CPU power which is well isolated on all mobos.

.bh.

[Karlito]

I'm having the same problem with an NSK2400 power supply, though with an ABIT NF-M2 motherboard. Mine does power down though.

It sounds like the same problem discussed in a previous thread, titled "Antec PSU buzzing with hard drives???". (my first post, forum won't allow a URL..)

Any suggestions on a power supply to replace the stock one? Would like to use a Fortron fanless PS, but the NSK2400 isn't really designed for that (the optical drive and power supply compartment is isolated from the CPU and hard drives).

[zepper]

I have three SU-380 PSUs here now and none of them makes noise to any significant degree whether lightly or heavily loaded.

.bh.

[PenDragon]

It sounds like the same problem discussed in a previous thread, titled "Antec PSU buzzing with hard drives???". (my first post, forum won't allow a URL..)

Here's the URL: viewtopic.php?t=37023&sid=bf74ed016df4e ... c7db193652

[Chris Chan]

Most Antecs are oem Seasonics or CWTs actually; it's a shame that they do not perform like them.

CWT (Channel Well Technologies) is nothing really to aspire to xD. They're about the level of Sirtec/High Power: not crap like Deer or Powmax, but not a FSP or Seasonic either.

[matt_garman]

FWIW, I'm on my third SU-380. The first one worked for a couple months or so, then just died (wouldn't power on). The replacement whined, worse under load. This was with a Chaintech 7nif2 (socket a) motherboard and later a Biostar Tforce6100-754 motherboard.

Now I'm on the third one, running an Abit NF-M2 motherboard, with no problems so far. (Knock on wood.)

Though it was frustrating to have two power supplies be faulty, I didn't have any problems working with Antec to get the replacements.

Matt