Motherboard – CPU damaged by power supply

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, it took my motherboard and both hard drives with it. 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 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 of all, change the power supply. The PC will get power and the fans will spin, but will the motherboard POST? If not, you need to remove other components first. If you have two bars of memory, remove one bar at a time and try starting over. If it fails, reinstall the one you removed and then remove the next one. If the boot still fails, remove both memory devices and install another device that was not in the PC originally. If that fails then you can remove the memory so that’s not the problem.

The next thing to do is to reset the CMOS to default settings. This can be achieved by a reset jumper on the motherboard. The jumper must be located very close to the CMOS battery. The battery is about 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 a slot. If you are having difficulty with this, an alternative method is to remove the battery for a minimum of half an hour. Check 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 that didn’t work, you can try unplugging your hard drive and see if the motherboard is posted. From experience, this is a long shot, but you should try it first. If still 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 them both. 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 is working 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 operating system fails to load due to 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 installation 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 doing 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 you reformat.

Good luck!