Is my PSU an expensive brick?
May 9, 2011 9:35 PM   Subscribe

Did I bork my power supply?

So I'm rebuilding an HTPC and everything is going smoothly. I've posted nicely on a first run, installed Windows 7 on an SSD boot, all updates, drivers, etc. Graphics look good and everything seems in order. As a last step, I pop in an extra pair of HDDs to complete the box (I left these out to leave space in the chassis in case). Connect and flick on my power supply and... nothing. I reseated everything, tried disconnecting the additional drives, and nothing has worked. The lights don't go on on the motherboard, the CPU fan or any chassis fans don't turn on, I get no signal, and the supply is silent with its built in fan off. All peripherals were otherwise tested and previously functional, including the power supply which had done fine through prior builds.

What gives? Is it time for a new PSU and how could I have bricked this by plugging in a few SATA cables and an additional modular power cord?

Specs if it matters:
-- Power supply: SeaSonic X650 Gold
-- MB: Gigabyte 890FXA-UD5
-- CPU AMD Phenom II X4 905e
-- RAM: G.SKILL 4 x 2GB 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666)
-- Video: PowerColor Go Green! Radeon HD5750 1GB 128-bit GDDR5
-- Drives: 2x Hitachi Deskstar 3 TB, OCZ Vertex 2 60 GB.
-- Cooling: Scythe Shuriken Rev. B, 2x Noctua NF-B9, 2x Noctua NF-R8
-- Case: SilverStone LC20B-M
posted by drpynchon to Computers & Internet (13 answers total)
Stupid question: is the power strip on, is there power at the outlet? (I sort of panicked because of that on my last build).
posted by Monday, stony Monday at 9:44 PM on May 9, 2011

Yeah, I came to that possibility late, but it's in order. The power strip is on, all other electronics are running through it fine and switching outlets on either the strip or the wall didn't fix the problem
posted by drpynchon at 9:46 PM on May 9, 2011

SeaSonic's site says that if the motherboard has a fault, the power supply won't power up. Do you have another motherboard to test? Isolate the faulty component.

They also say that their power supplies have 60 month warrantees, so if there's something wrong with it, you may be able to get it replaced. You should go to and then call them.
posted by Mad_Carew at 9:49 PM on May 9, 2011

I have another motherboard but I hate to go through the pain of cleaning and reapplying thermal grease and such since this is my only CPU/heatsink. Is that really necessary? The motherboard was working great with the same device shortly prior to this.
posted by drpynchon at 9:55 PM on May 9, 2011

Do you have a power supply tester? They're like $10-20 and very handy for this. In my experience, motherboards fry far more frequently than power supplies, and if it's a new MB it may just be defective.
posted by kavasa at 10:22 PM on May 9, 2011

I went ahead and switched to a backup board and the PSU didn't work there either. I think I'm going to get in touch w SeaSonic.
posted by drpynchon at 10:37 PM on May 9, 2011

You can test the power supply by shorting the green wire to a black wire on the motherboard connector with a piece of wire (which fakes the "power on" signal from the motherboard). Unplug everything else when you try this, of course.
posted by neckro23 at 10:55 PM on May 9, 2011

Is it time for a new PSU and how could I have bricked this by plugging in a few SATA cables and an additional modular power cord?

The total wattage your system (as listed) could take is only around 350-400W, and that's if everything is running max. You weren't pulling near that wattage on boot. Seasonic is also a known good PSU manufacturer; they OEM a lot of PSUs. It really sounds like it just died, you didn't kill it with anything you did.
posted by Mister Fabulous at 12:07 AM on May 10, 2011

For the record, you should be able to get POST beeps out of a motherboard without plugging in a cpu or any other components.
posted by rhizome at 12:38 AM on May 10, 2011

If everything was working prior to you adding another couple of hard drives, its possible you've just knocked a connection out while you were fiddling. Before buying new components etc. Try disconnecting everything and reconnecting it. I've had it happen plenty of times that everything looks fine and connected but its not working, then you unplug it properly and plug it back in and it works.
posted by missmagenta at 12:51 AM on May 10, 2011

Also - have you tried unplugging the power cable at the socket and unplugging it from the PSU? I've had PSUs that seem to have a sort of fail-safe that makes them non-functional after a problem until you disconnect it completely and reconnect it.
posted by missmagenta at 12:53 AM on May 10, 2011

When you're replugging everything, test it just before you add back that final pair of HDDs. That's when the lights went out the first time.
posted by TruncatedTiller at 3:45 AM on May 10, 2011

Borrowed a different PSU and everything else works fine. SeaSonic is going to replace this thing. I do wonder if I somehow shorted something in it but who knows. Their service is great. Thanks everybody.
posted by drpynchon at 2:12 PM on May 10, 2011

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