No POST, likely burned out PSU, CPU, or Mobo. A few (maybe) telling symptoms, though

LobsterHegemony

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Aug 6, 2013
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Self-built PC running Win7. Apologies, but it's been so long since I last did work on it, that I can't quite remember all the nuances of the parts.

Motherboard: Gigabyte GA-P35-D53L. Power LED is OUT PSU: Antec 550W ATX CPU: Intel Multicore, fits socket 775. Can't for the life of me remeber the exact model number

I was actively using it when my computer just dropped dead. I didn't jostle it at the time or anything, so I don't think I could've caused a short anywhere. There had been a few red flags earlier, including one or two short freezes (10 secs)- very atypical for my rig, but I brushed it off.
So now it won't post at all. No beep codes whatsoever, nothing. I tried removing all the "easy" components (video card, RAM, HDD), but no go. I'm assuming something expensive is probably fried, but it's hard to know what.

There are some interesting symptoms, though. First, when I flip the case switch on the PSU from off to on, I will get a light flash on my keyboard. Second, the first and ONLY the first time I attempt the power button after flipping on the PSU case switch, all of my fans will twitch. Like they're about to spin up, and then just give up. Subsequent power button presses do not yield a similar twitch unless I switch off the PSU case switch, wait 5 secs for that signature whining sound that it's powered down, and then flip it back on. This means something, but I have no idea what.

Also, my motherboard light is out. Completely. And while I can't actually find reference to the motherboard LED in my documentation, it has to be there. I haven't opened my case in so long, that I can barely recall, but I mean, everybody has a motherboard LED, right, right?

So that's about it. Does anyone have an idea what these symptoms might be pointing to, or additional steps I might take to isolate the cause?

PS. I was told to try the "paperclip test" for the PSU, which I'll do as soon as I'm home from work.
 
Solution
It does indeed sound like the PSU died. The 'paperclip trick' will only tell you that the PSU and its fan run. You will need a volt meter or PSU tester to check output voltage. Even then, with no load the voltages may appear normal... even if the PSU is failing. If your MB light is out, that is another indication the PSU isn't putting out. And the whine could be simply a bad fan bearing, or electrical noise. Either way, it seems like the PSU is bad.

And no, not all MB's have an LED indicating light to show it is powered up. But Asus has always been good about that. And some Gigabyte boards have that too.

clutchc

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It does indeed sound like the PSU died. The 'paperclip trick' will only tell you that the PSU and its fan run. You will need a volt meter or PSU tester to check output voltage. Even then, with no load the voltages may appear normal... even if the PSU is failing. If your MB light is out, that is another indication the PSU isn't putting out. And the whine could be simply a bad fan bearing, or electrical noise. Either way, it seems like the PSU is bad.

And no, not all MB's have an LED indicating light to show it is powered up. But Asus has always been good about that. And some Gigabyte boards have that too.
 
Solution

LobsterHegemony

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Aug 6, 2013
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Yep, you're right. It was the PSU. Just tested with a good one I borrowed from a roommate. Now all that's left to do is a full replacement, followed by finding out what, if anything, got destroyed when it died.
 

LobsterHegemony

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Aug 6, 2013
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Thank you for the reassurance. Any recommendations on a decent 550W+ in the under $100 range?