More Extensive Testing
So the capacitors are in fine shape, but the motherboard will still not post. Lets examine a few reasons why, and how we can check.
- Motherboard or component is grounded out to the case
- Memory has failed or is poorly connected
- Poor connection between components
- Power supply failure
Make sure that the computer is OFF before attempting any of the steps mentioned below. For safety, unplug the power from the computer. When its time to test it, plug it back in and then remove it when done testing. If you do not have a static strap to keep your body grounded to the computer, simply touch the computer before you touch any components.
If your computer has been acting normally and it is suddenly not working, its not likely grounded out as mentioned in the first bullet. It is possible however that one of the USB ports on the front or back of the computer has been damaged and is shorting out. Physically examine all the USB ports. Do they look OK? Will a USB cable plug into them easily? If one of the USB ports on the front of the computer appears to be damaged, locate the cable between it and the motherboard, and then unplug the cable from the motherboard. Turn on the computer. Does it post? Great! You've found your problem. No? Lets move on.
Now lets turn to the memory to see if it is causing the problem. The memory is a long "stick" that is plugged into the motherboard. Most of them look like this. We need to reseat (remove and put back) the memory. There will be retaining clips on either side. Unclip them by moving them away from the memory stick. Now you can raise the memory stick away from its socket. There's no need to take it out all the way. Just unclip both sides, pull it out until its not touching, then put it right back in. You'll feel a firm 'snap' when it goes in all the way. Make sure the clips are secured before proceeding. If you need explicit instructions, check out this great youtube video. Power the machine on. Does it POST? Great! Reseating the RAM took care of it. Not so great? Well... lets check some other things.
Each component in the computer plugs in with a cable to the other components. Unplug each cable and plug it right back in. For any additional cards that are plugged into the motherboard, remove them and reinstall them just like you did with the memory. Hopefully at this point, it posts. If not, then carefully note the location of every cable that plugs into the motherboard (here's where you get to use your notepad), and remove all of them with the exception of the power switch cable and the power supply cables. The power supply cables are multi-colored and lead to the power supply. The power switch cable is usually two twisted wires, one green and one white. If you're not sure, just trace it from the power switch to the motherboard. Try turning it on. Hopefully at this point you have a computer that posts. If not, there's one more way to tell if your motherboard has failed or not.