I built a pc last night, and as soon as I plugged it in, it turned on itself, then turned off after a few seconds. I turned it back on, and it turned off again. I didn't plug in the reset switch, so maybe that's why. (I lost the cord somehow) I also didn't put in a disk drive.
you only need the following components plugged in to get a POST test of some kind. power supply mother board CPU {heat sink and fan} memory video chipset or video card keyboard monitor if you assemble those together like they are supposed to be, then when you turn it on it should boot to a screen mentioning a missing hard drive or maybe operating system. if you don't get that far then one of two things is wrong. either you incorrectly connected a piece {or pieces} of hardware or the hardware is non functional and it needs to be RMA'ed. the symptom you describe makes me think you don't have everything connected correctly. what i would do is tell you to take it to someone who knows what they are doing. i don't mean to insult you it is just the simplest way to fix your problem. on the other hand if, like me, you don't like simple shit then read on my friend. post the exact models and mfg's of the components you have. we might or might not need them but it is a place to start. aside from that, get the motherboard guide out and see what needs to be connected for power. make sure it is correct. after the power is correct make sure the CPU is in the socket correctly and make sure the heatsink and fan is clipped in correctly and the fan power is connected the the CPU header on the motherboard. again, its in the motherboard manual. after the CPU make sure the memory is inserted into the correct slots on the mother board. ya, the fuckin manual again. if you have a motherboard with on board video then video is all good. if it is a video card then make sure it is in the correct SLI / cross fire slot. make sure the external power from the power supply is connected to the video cards {or cards}. by now, you should know to look in the mother board manual for slot placement. as for power, look in the video card manual. plug in the monitor so you have video. if you have a video card make sure you have the monitor plugged into the video card and not the on board video. it happens... plug in the key board. with all of that done correctly it should boot. if it is cycling power as you describe, then you definitely need to make sure everything is plugged in correctly. it could be power, or video card or memory or CPU {heat sink and fan too!}. you just have to go back through it. post back with results! good luck!
Ya I just forgot to plug the ram in.But now I can`t boot cause my hard drive is not detected. I don`t have a power cord with the hard drive, but it worked without a power cord in my pre built computer. The hdd isn't formatted and has win 7 on it. Also the cpu sometimes doesn't turn on. Sometimes it does. My mb seems to be of low quality, it has 4 ram slots, labelled a1 a2 b1 b2. The manual says 2 blue slots are a1 and a2, I plugged them in there, but the bios says I`m in a1 and b2. My gpu won`t even fit in the sli slot properly because those plastic parts of the mb get in the way, and this is an sli mb.
ok, lets answer this in order of questions asked. Hard Drive- it sounds like you are saying that the hard drive was working fine in the previous computer. you had the data cable connected and working and you had the power cable connected and working. after installing it in the new computer you are saying that the data cable is connected and working properly but the power cable is not compatible / wont fit the power plug on the back of the hard drive? answer- the power supply of the new computer you have built has to have a power connecter of some kind that fits the back of the hard drive. if the drive is small enough, like a lap top hard drive or SSD drive, it might run off of the power coming through the SATA connection {the data cable} that connects the hard drive to the mother board. if you could grab a pic of it with your phone i am sure we can get this handled directly. just open the side of the case and take close pictures with definition. post them here. Memory slotts- i would install them exactly as the mother board manual describes. if it is still off then i would reinstall the ram so that the BIOS shows it as being correct. one of those two will get it booting. for the sake of argument, we coulld simpley install a single stick of memory. that gets us passed this problem so that we can get the computer to book correctly. when we have completed that step we can come back and handle this problem. one thing at a time my freind. Video Card- you are saying that the plastic parts of the mother board or video card are getting in the way of it fitting properly in the mother boards PCIX slot. are you saying that the actual connector on the bottom of the video card will not fit to the actual connector on the mother board? like they are incompatable? pictures would be great here and i am certain that in short order we could have this problem identified and corrected. so take close pictures with definition here as well. just line up the video card next to the place on the motherboard it is supposed to plug in at / connect to. then take a picture of the video card and another picture of just the mother board. hope that makes at least a little bit of sense you could also post the make and model of the hardware you are attempting to use.
Hard drive: in my previous computer it needed no power cord. I connected the power cord to the hard drive in my new pc, and the computer turned off a few seconds after I turned it on again. I unplugged the power cord, and it did the same thing a few times, but then stopped. Maybe a coincidence? Video card: it fits in the slot, but barely. It has to push against a sata connector to get in, and barely locks. And the cpu fan just had its own cord in the way. I moved it and it turned fine. I'll post pics on here in a minute.
Hard drive: the empty slot below is the power slot. this hdd came from a prebuilt and never had the power plugged in. The gpu pushing against sata connectors. it's just hard to get it locked in good.
Something probably isn't plugged in all the way. Same thing happened to me on my first PC build - the processor wasn't completely attached. Just rebuild it like another poster mentioned. A lot of mechanics just rebuild a whole engine when they can't figure out what is wrong. It's the best fall-back plan.
Hard Drive- you need the sata power connector that comes off of the power supply. you know it is the right connector because it will be the only one that fits. if for some reason your power supply doesn't have a SATA power connector, then you can get a molex to SATA connector for a buck or so. then you can connect power to the drive. and yes it does indeed need power to run it. the PC that the drive came out of could have had some proprietary deal as far as powering the drive, but that is a full size hard drive and it needs a separate power source to run it. Video Card- even if it is really tight, as long as the video card connects all of the way into the slot, then you are good. just make sure you connect power to the video card if it has power connectors on it. so, if you were to unplug the hard drive and turn the PC on, what message appears on the screen now ?
The bios screen comes up with no hdd in, just like before, and no hdd detected. I plugged the power cord in and it went straight to windows welcome screen. Thanks, I'll have to look into the pc turning off itself though, I'd bet it's the power switch not plugged in all the way, as Colt classic said. Thanks man.