last night I did something stupid. I was attempting to put in a new harddrive (well…and old harddrive from a previous computer,) into my desktop tower. It’s SATA, so it’s hot-swapable. However…when I went to insert the power connector, I had it backwards. :smack:
There was a small spark and the computer shut down. I waited a while, turned the PS switch off and on, and booted it up, and hey, it actualy still worked! I got to a Windows log in screen. I shut down, and then installed the harddrive, correctly this time, and went to boot back up…nothing.
Well, not totally nothing. The case fans turn on, and I hear the hard drives spinning (I took out the one I tried to install, it’s now just the two that were in therepreviously.) So the power supply seems to be fine, but I get no beeps, the CPU fan doesn’t spin (I really hope it hasn’t fried itself from the several times I’veturned it off and on.)
At any rate, I unplugged everything but CPU, RAM, and the video card, and nothing. Still just the case fans spinning (not even the video card fan, from what I can tell) and no beeps.
My initial guess is motherboard. Fuckity fuck fuck.
Sounds like you lost the 3.3v or 5v output from the power supply. The fact that the machine booted after the first incident implies that the motherboard is OK.
Since it did boot once after the spark … when you were pulling things to get to bare bones are you sure you didn’t also unplug the power supply line to the motherboard or the wire to the power button?
I think beowulff is right: you might have just cooked part of the PSU. One way to check is to short the green wire on the motherboard cable (see this article) and see if the PSU is able to run on its own.
I think it’s unlikely that you cooked your motherboard, because the data connector doesn’t carry any serious current or voltage, and that’s the only line that runs to the motherboard. If you really gooned it up, it’s possible that you cooked the SATA controller on the motherboard, but even that seems unlikely to me - you’d at least be getting beep codes.
Well PSU is a better option than mobo. I replugged in all the PSU connectors so it’s not that. But my case fans are powered by the 5v rail from the molex connectors and they run and light up. I’m not using the one line that sparked, and the others seem fine.
Wha? I thought SATA connectors were - pardon the expression - idiot proof? How did you manage to get it backwards? There shouldn’t even be any electrical contacts on the other side of the plug that could touch the wrong way around.
It was an older sata drive that has both molex and sata power connectors and I used the molex one cause it was easier. It didn’t go all the way in cause it wouldn’t fit but a pin made contact
Ah, there we have it. Molex connectors aren’t supposed to be hot-pluggable. :o
Let’s see, it’s impossible to swap pins 1 and 4 because of the bevel edge. So you must have shorted one of the outer (either 5V or 12V) to the middle (ground) pins. Didn’t even need to have it backwards for this.
Maybe you’re lucky because this means 1) the board and the other components likely didn’t see any overvoltage, and 2) most of the return current probably went through the metal case, not through the data cable (if you connected it first). Looks like one rail got hit and finally went dead during the second start.
I don’t think it was just the power supply. I replaced it, and I get the exact same problem. Here’s the summary:
PSU fan spins.
Case fans spin when connected (right not they’re not.)
Video card fan spins.
Hard drives sound like their spinning up when connected (right now they’re not.)
CPU fan does NOT spin.
All I have plugged in are CPU, RAM, and video card and I get nothing. The fans (except CPU) spin for a few seconds, then they shut off, and repeat this process until I flip the hard switch on the PSU.
On the occasions that I’ve seen this particular behavior from a system, 99% of the time it winds up being a case of a badly seated expansion card (usually the video card) or memory module. I know it sounds completely stupid – you weren’t doing anything with the video card or the memory. That’s exactly what I said the last 3 times this happened to me. And in any case, the fact that you got the system to boot all the way to the Windows login screen implies that there’s nothing wrong with the electronics. I’d put good money on this being a mechanical problem, not an electrical one.
Sometimes, just fumbling around inside your case to pull connectors loose or to mount a hard drive can somehow cause enough “collateral motion” to barely unseat one of the above. For example, maybe in pulling the power connector loose from the HDD, you jostled the PSU’s hydra cable. And just maybe that jostle yanked a tiny bit on the auxillary power connector to your video card, causing one edge of the card to pull up just a millimeter or so.
I think you’ve got the right idea by disconnecting everything from the PSU until you get the system to post. So I’d still leave everything unplugged for now. Just try pulling the video card out and re-seating it, and do the same with the memory modules. You might blow out their respective sockets if you notice any dust in the case. Also, if you have more than one memory module, try getting it to boot with just one of them before you plug them all back in.
Everything has been pulled and reseated, still nothing. The CPU fan almost spins, then stops. How the fuck would that even get damaged? And did I basically fry my CPU now that I’ve turned this thing off and on so many times without the fan?
Have you reseated the CPU too? Possibly you bumped the heatsink at some point and broke the bond of the thermal paste causing it to instantly overheat and shut down.
Damn it…I don’t have any mobo or spare CPU to swap out to test. Well, rather than keep throwing money at it by buying parts before knowing if I need them, I’ll probably just take it to a repair place.
