My Lenovo Dual core 2.4 ghz, 4 gigs ram, 280w psu (probably the cause of the frying), nvidia 7750 overclocked graphics card, and there's probably more that I'm not listing, seems to have given up. Last night I was playing WoW and listening to pandora and all the sudden my computer made a "frying/hissing" noise and shut off. There was also a terrible burnt smell that was coming from the computer. I spent the rest of the night trying to figure out what was wrong with it. Today, I went out and bought a new power supply and tried it in it and nothing happened, only the green light indicating the power was on in the front was on. This was what was happening with the old PSU as well. I eventually took the processor out and put it into another computer and it didn't work in that either. My graphics card isn't being recognized in the other computer either, and the computer supports pci express cards. Pretty much, what I am wondering is whether my motherboard fried and took everything that was connected to it with it, or was it just the power supply, motherboard, or processor? The hard drive works fine in the computer I put it in, just not the graphics card.
Sorry for the long question, and any answers would be awesome!
If you fried both your CPU and your graphics card it's unlikely your motherboard is undamaged.
It's most likely that your underpowered PSU caused a massive short resulting in a situation similar to lightning striking your system thus damaging most components.
All experts agree that the PSU is the most important part of the system. A poor PSU can create all sorts of issues with insufficient voltage or even catch on fire.
That "hissing" noise was the short causing increased electricity through components damaging them beyond repair.
CPU's often have some voltage protection but such protection is insuffient if the change in voltage/current is too high or too fast.
It probably survived because it's slightly more isolated. It has a direct power connection to your PSU, but there are several different choices of power (voltage) such as +5, +12, +3.3 etc.
The scenario MAY have been this:
1) +12V power inside PSU fails causing a short circuit
2) Wall power temporarily streams to your motherboard
3) this power is then distributed to other components using this same voltage power path
4) the short circuit then opens up as one or more components burn up creating a break and stopping the current flow
Keep this in mind next time you build a system or update an older one. Most prebuilt systems are designed to power the existing components but not an upgraded setup such as an added graphics card.
You don't need a super expensive PSU, but it's good to purchase a known name brand. A good, moderately priced PSU of even $60 will often have extra protection circuitry to safeguard the rest of the computer even if it fails.
It's also worth getting a surge protector. This protects against AC spikes damaging the PSU, but also will help prevent some surges if the PSU fails first. A surge protector is unlikely to be nearly as good as what the PSU manufacturer can design for its own PSU.
There are a lot of good articles on PSU's but in general it's fairly easy to buy by Googling, looking at customer reviews and estimating the power requirements.
Sounds like Lenovo set this up for failure, lol. They only provided a 1 year limited warranty. Thanks for the answers though guys, looks like I'll be looking to build a brand new computer. Only thing is that I'm on a budget of about $300 dollars.