I am trying to build my first system in well over a decade and I am running into a problem. Here are the components:
DH55HC Intel Motherboard
i3-540 3.06GHz 4MB LGA1156 CPU
Corsair Dominator 4 GB PC3-10666 1333MHz 240-pin Dual Channel
Intel X250 80GB SSD
Antec Green Energy-Efficient Power Supply EA500D
I have everything in the case and connected (as far as I can tell) properly. I can see power is getting to the board, based on the green light showing in the bottom right hand corner. When I hit the power button, the CPU and Case fans will spin for just a split second, then it is like the power has been shut off. A second or so later, it does the same thing over again.
I have tried shifting the memory around and used a PCI video card from an old computer (I saw some articles stating that the i3 and i5 sometimes have issues with integrated graphics), but I can't see any improvement. I am not getting to the Intel splash screen, so I am guessing I have a hardware issue of some sort, but I don't have a good idea of where to go next.
Skip the pci video card. The onboard video will work. Check for anything touching the board from underneath or even a bent metal tang from the backplate. Make sure the 4 pin 12v lead and 24 pin atx connector are making good contact. I always take out the board and do a bare post before mounting it in the case, even if I have to remove the power supply for the leads to reach. Just one stick of ram, monitor vga lead, cpu/heatsink, and the keyboard. touch the power switch pins with a screwdriver and be sure the power supply switch in back is on.
Breadboard with just motherboard, CPU & HSF, case speaker, and PSU.
Make sure you plug the CPU power cable in. The system will not boot without it.
I always breadboard a new build. It takes only a few minutes, and you know you are putting good parts in the case once you are finished.
You can turn on the PC by momentarily shorting the two pins that the case power switch goes to. You should hear a series of long, single beeps indicating memory problems. Silence indicates a problem with (in most likely order) the PSU, motherboard, or CPU. Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.
If no beeps: Running fans and drives and motherboard LED's do not necessarily indicate a good PSU. In the absence of a single short beep, they also do not indicate that the system is booting.
At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.
The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.
A way that might be easier is to use the main power plug. Working from the back of the plug where the wires come out, use a bare paperclip to short between the green wire and one of the neighboring black wires. That will do the same thing with an installed PSU. It is also an easy way to bypass a questionable case power switch.
This checks the PSU under no load conditions, so it is not completely reliable. But if it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.
If the system beeps:
If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card.
Silence, long single beeps, or series of short beeps indicate a problem with the memory. If you get short beeps verify that the memory is in the appropriate motherboard slots.
Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST. At this point, if the system doesn't work, it's either the video card or an inadequate PSU. Or rarely - the motherboard's PCIe interface.
Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step. It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.
First of all, thank you very much for your time replying to my issue. As it turns out, I fell prey to the issue in huge red letters on the install and troubleshooting guide jsc had linked in his post. I did not have the CPU power connection plugged in. A simple pop in place and I can now get to the Intel splash screen.