It should be looking for your hard drive. One of the power supply connections needs to plug into that. Depending on the type of hard drive you have, the connector type will vary. I'd think the first thing you need to do is make sure it's attached properly to everything that needs power from it but I cannot help much in this regard. All drives will need power. The MB will power and it's likely an additional CPU power connector will be needed. The MB connector will be the largest. You can't miss it. It's rectangular and will have 2 rows of either 10 or 12 pins each. The CPU connector attaches to the motherboard and generally has 4 pins on a square connector. IDE hard drives and CD ROM drives use a 4 pin "molex" which will have two black wires, one yellow and one red. SATA drives have their power wiring wrapped in a sheath and aren't individually visible. It sounds like you're ok as far as what goes into the MB or you'd get no BIOS power on self test. I'd be checking the hard drive connections first. You should also be able to interrupt the POST to see if the hard drive has been detected. If it has and listed in the boot order but still shows a boot failure, you have another problem.
HELP!! A couple of days ago got home from work only to find my computer not working. Discovered it wass my poweer supply. Got a new one at best buy and got it installed. then turned on the cpu and i have power.
But then i get a "disk boot error message". so i tried one of the recovery disks (thinking that is what it meant but this did not work) (so what is a boot disk) that i made when the computer was new and that did not work. ONE MORE THING: the poweer supply did not come with instructions. And of course in my hurriedness i did not make a hard copy of the spots where i unplugged things. Next time i will use paper and pencil!!! But i know that i only unplugged 3 or 4 places. there is a flat looking plug that seems like it needs to go somewhere but i cannot find out where it goes. It looks like it has 4 little prongs in it but i have no place to put it. the cpu I have is about 3 years old from HP. Any help you can give me would be appreciated.