Need help on a computer diagnosis

Yesterday my computer started putting up red pixels well play DayZ standalone so I powered it off and took my Nvidia GeForce GTX 760 and cleaned it but then I noticed that only one out of three of my case fans were working so I found one of my fan 4 pun connectors labels p2 and my friend said it should be fine for me to connect it to the Cha-Fan 1 4 pin slot so I put it in. After I powered on the computer though I heard a quick crackle noise and a puff of white smoke came out of the top of my computer so when I heard the noise I pressed the power kill switch and unplugged the computer and took the 4 pin out of the Cha-Fan 1 slot and powered up the computer and it worked fine but I don't know we're the white smoke came from and what happened is there a chance the fan I hooked up fried or could something much worse have happened.

Was it white smoke or dust?

Sounds like it was dust, especially if the fan hadn't been working for a while. That fan probably had a bit of dust built up in it.

Unlikely the fan could be fried as it can only be wired correctly or not at all.

@GTR12: it was white smoke.

The fact that there was a crackle to me says there is a good chance the power supply is about to die. That sounds exactly like the few times I've seen a power supply die.

@jesseh1995:

Doubt it was smoke as the PC works now.

@GTR12: it was smoke that's Forsure because after word there was a burnt hydrogen peroxide smell

Does the PC work or not?

Probably just dust, although a capacitor may have blew. Your computer might work even if a capacitor blows anyway, but it will put more stress on the remaining ones.