If you're having no luck, here's my recommendation.
Like it or not, pull the motherboard from the chassis. Lay it on a non-conductive surface, not a silvery metallic, or anti-static bag (of course, if you put it on wood, make sure you don't care if the surface becomes scratched.)
Remove all of the RAM modules from the motherboard, noting how they feel as they are removed. Too loose, very tight, wobbly, clips half open, etc.
Consider very carefully, removing and reinstalling the CPU. If you did not do the initial installation of it, or were inexperienced at the time, I would be suspect. For this procedure, you should have handy some isopropyl (rubbing) alcohol, q-tips or perhaps a coffee filter, and new thermal interface material that you can reapply, otherwise, do not remove the heat sink from the CPU.
After you have the motherboard laid entirely bare, remove the button battery from it. Now with the battery removed, either locate the jumper for resetting the BIOS, and move it to the reset position and leave it there, for at least 60 seconds, or short the two contacts of the battery holder with something small and conductive like a butter knife or screwdriver to drain the internal capacitance of the BIOS. Either will accomplish the task, which is to reset the BIOS to defaults. When looking at the BIOS reset jumper, it's important to realize, if it's already been messed with in an attempt to remedy the non-booting computer, it's possible somebody put it into the reset position and forgot to put it back. The computer will invariably fail to boot with that little jumper in the wrong position, so small as it may be, it's critical you make sure it's where it belongs. Reinstall the battery after you have cleared the BIOS.
After resetting the BIOS, continue by verifying that the CPU slots in without much force. ZIF socketed CPUs generally drop in under their own weight, but it doesn't hurt to ensure each corner is fully seated by pressing down on them as you throw the lever down to relock the CPU into place. One or more bent pins could be the cause for the CPU not seating easily. Be extremely careful if you try to miss with a bent pin, they are obviously fragile.
After cleaning and reseating the CPU, and allowing any residual alcohol to evaporate, apply a chick-pea sized portion of the CPU paste in the center of the integrated heat spreader. Clean and reseat the heat sink and fan. The pressure of the heat sink and the thermal cycling of the CPU will spread the paste for you. Verify the CPU heat sink's fan is properly connected to the CPU pin header on the motherboard. It is possible under some conditions to have a no boot scenario, if the CPU fan is thought to be faulty by the BIOS. This will depend on the BIOS, as not all will have this behavior, but do be sure which pin header is used for the CPU fan.
Tom's Hardware instructions for properly applying thermal paste:
http://www.tomshardware.com/reviews/cooling-air-pressure-heatsink,3058-9.html
Next, install one, and only one RAM module. If you want to be anal, look for whichever RAM slot is considered to be the #1 slot. Maybe it will be in the board's manual, maybe it will be silk-screened to the board. If you can't locate it, use the slot closest to the processor.
At this point, remove the power supply that is being used with this build from the chassis and connect it to the motherboard. It should go without saying, the power supply should be unplugged this entire time, and if you will look on the back of it, there may be visible a small toggle switch having a 0 and a 1. The switch should be in the 0 position, if present. This is mains off. When plugging the power supply in, make sure that the CPU power harness is connected. This will be either 4 or 8 pin, and located near the CPU's socket. When plugging in the main harness, use all 24 pins if possible.
Now, if the system has on-board video, you are done adding components to the system in an attempt to troubleshoot it. Plug your monitor into the on-board video output, and nothing else. Don't use an add-in graphics card, don't plug in a keyboard, or a mouse, or anything else.
Plug in the power supply, flip the switch on the back of the power supply (if present) from 0 to 1, and using a small conductive screwdriver or butter knife (whatever's handy), momentarily (about 1 second) short the two-pin contact of the front panel connector on the motherboard that would normally connect to the power switch.
You will know if you shorted the right two contacts if your CPU fan jumps slightly, or begins spinning as you would expect.
At this point, you're running the least number of variable parts, and hopefully the system POSTs, the screen turns on, and you can proceed to adding back components, one piece at a time.
If not, short the same two pins again, momentarily at first, or for up to five seconds, until the system forces itself to power down. Be careful which two pins, as you don't want to short anything else out for any length of time. If you're uncomfortable with this part, you might be best advised to retrieve an old power switch from an old, junked computer case. You can just attach the two-wire lead and push button switch for benching.
Once the computer is off again, turn off the power supplies rocker switch (if present). This cuts any stand-by power that it may be providing to the board without your knowledge. If the switch is not present, unplug it. Wait perhaps 30 seconds or more for any residual capacitance in the power supply to discharge, and then you can go back to troubleshooting. Swap the one RAM module for the other. Try POSTing the motherboard again.
If you have the same results, swap the power supply for a different one, and try again.
Once you've managed to get the motherboard to post, or after exhausting all components to this point, then you may try your add-in graphics card. It should not matter which output of the add-in graphics card you use, as all should show BIOS output at the same time. Only older graphics boards required a primary screen for BIOS output. Manufacturers overcame this nuisance by just cloning all of the outputs when in certain modes.
If your add-in video card doesn't work, try another one.
Continue this until you are reasonably satisfied things are working, or are not going to.
If you finally can get nothing to boot to at least the BIOS POST screen, the next step is to start testing individual components such as the CPU, RAM, and any add-in boards in a known, working system. It's a pain, but this tells you what components are serviceable and what components are not.
Note: When installing the motherboard into the chassis, if you got little paper insulators with the package of hardware for mounting the motherboard, don't use those. Your motherboard is suppose to be fully grounded. Using those paper washers doesn't help with grounding.
Hope this helps. I'm tired of typing now.
Facebook
Twitter
Instagram