ive just got a new coputer and when i plugged it in it blew up- i mean went pop and blew smoke...and now it is dead- wont turn on.
Now ive noticed that the voltage switch was on 115v instead of 230v. This means that the computer has been majorly overloaded. Is this a blown power supply, motherboard, CPU?? can it be fixed, or is it 'bye bye computer!'?????


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Open the computer and assess the damage. If it blew up and puffed smoke, then you should see evidence of burning, hard to miss.

Now ive noticed that the voltage switch was on 115v instead of 230v.

I think you meant the other way around.. anyways, that difference in voltage will certainly cause an overload. Fortunately, if that new computer is not complete garbage quality, the power supply will have protections against overloading the motherboard. Usually, power supplies act as an electrical buffer. A full explanation of this would be too long, but long story short, the damage should be limited to the power supply (unless the power supply is of extreme poor quality).

I am almost 100% sure that replacing the power supply is going to fix it. At least, it's worth a try.

If you have a 230v main power and the system was switched to 115v, then the increased amperage required to deliver the required load can have caused serious damage to the system, although many power supplies have limiter circuitry (fuse or circuit breaker) that can limit the damage to the system. As Mike suggests, a new power supply may work, but there are no guarantees. I have seen this situation fry motherboards in the past. :-( Anyway, voltage drops, current goes up, the magic smoke is let out...

although many power supplies have limiter circuitry (fuse or circuit breaker) that can limit the damage to the system.

It's not really a matter of having fuses or breakers, but some do have those as an extra protection (usually a fuse.. but it is sometimes soldered into the board!?!? Tell me what's the purpose of a soldered fuse!!). What I was referring to was the fact that an AC to DC converter (commonly known as a power-supply) work through induction through a magnetic core (a lump of iron), which is why they are so heavy, and a series of large capacitors. But basically, you have a part of the circuit on the "AC side" and part of the circuit on the "DC side", and energy is transferred via the magnetic core. Normally, if a competent engineer designed the power-supply, a power surge on the AC side should not cross over to the DC side, meaning that the AC circuitry will fry, while the DC circuitry (and all the computer components connected to it) will not feel much except a sudden shutdown when the AC side is busted. So, usually, good power-supplies that have a fuse, have it mainly to protect the AC side from frying. A good power-supply will have both of these features because a fuse cannot protect from everything (like electric resonance).

A simple way to guarantee that the DC side is protected is to design the magnetic core to be just the right size such that it will saturate (magnetic saturation) before too much power crosses over, and when that happens, the power surge on the AC side has nowhere to go except up in smoke (i.e., by frying other components, since you can't really fry a lump of iron, unless the power surge is really massive). The mistake that is often done in cheap power-supplies is that magnetic core is chosen as "big enough" with a generous margin (iron is cheap), meaning that it can let through far too much power, and thus, fry the DC side instead.

But as you see, this is a case of failure-mode engineering, i.e., engineering the thing such that it fails gracefully (e.g., fries the AC side but nothing else, which is similar to the way cars are designed to be "soft" outside such that an impact does reach the inside, because it's better to have a crushed front-end but keep your life, than the other way around). And this is one of the things that often get cut within companies that are trying to cut every corner to deliver the cheapest products, because it requires a lot more testing. That's why I said this is a matter of the quality of the power-supply.

I beleved the PSU is shorted for sure, replace the PSU.

If the mobo still not be able to power on, the mobo and other parts could likely get damaged as well, check for any damaged capacitor as well.

Hope this helps.
Tech Manager, WPTinc.

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