The number one cause of damaged motherboards and/or CPUs is a faulty power supply. Several years ago the power supply for my home PC literally caught fire. When the power supply went out, it took my motherboard and both hard drives. Needless to say, I lost a lot of data that I didn’t have backed up.
When customers bring their PCs in for repair with the “I press the power button and nothing happens” symptom, it’s all too obvious what happened. If it was some kind of power surge or an internal fault with that power supply, it doesn’t matter, that power supply is toast. Now you need to find out if the damage is limited to the power supply or if you removed other key components as well.
First thing, change the power supply. The PC will get power and the fans will spin, but the motherboard will POST? If not, you need to remove other components first. If you have two memory sticks, remove one stick at a time and try starting again. If it fails, reinstall the one you removed and then remove the next one. If startup still fails, remove both memory devices and install another device that was not originally in the PC. If that fails then you can remove the memory so it’s not the problem.
The next thing to do is to reset the CMOS to the default settings. This can be accomplished by using a reset jumper on the motherboard. The jumper should be located very close to the CMOS battery. The battery is the size of a quarter. Nearby you should see three pins with a jumper on two of those pins. To reset the CMOS, move the jumper over one slot. If you are having difficulty with this, an alternative method is to remove the battery for a minimum of half an hour. Consult your motherboard manual for exact instructions. If you don’t have the manual, you can find it online with a little research.
If the CMOS reset worked, GREAT! All you have to do is reset your clocks and you should be in business. If it didn’t work, you can try unplugging your hard drive and see if the motherboard posts. From experience, this is a long shot, but you should try it first. If you still have no luck, then either the motherboard or the CPU or both are bad.
Now there is no sure way to determine which of the two is bad without replacing one of them. The danger of this is that if you guess the CPU and it was the motherboard, when you replace the CPU with a new one, you will most likely damage the new CPU. Therefore, it is advisable to replace both of them. If you don’t, you could end up spending a lot more money than you originally planned.
Of course, now that you’ve changed the motherboard and CPU, all the hardware works and you think you’re out of the woods. But that is not the case. When you try to start Windows, 9 times out of 10 the OS won’t load because of the new motherboard. If you replaced the motherboard with the exact same model, you probably won’t have this problem. If you replaced the motherboard with a different model, then you have two options:
1. Try to do a repair install of Windows. You will need the Windows disk to accomplish this.
2. If the above fails, you will need to reformat your hard drive, which means erasing the entire drive and performing a clean install of Windows.
If you have valuable data on your drive that is NOT backed up, you will need to start looking for ways to recover that data BEFORE reformatting.
Good luck!
