Dead PSU - Help needed

[Debat0r]

So, I'm quite sure is dead.
The thing I want to ask you guys is what might be wrong with it, and if I can repair it.
Let's start at the beginning: I've got a Corsair CX750M, and every cable is black, except for the 24Pin motherboard connector. So I decided I wanted custom sleeves on those cables. I ordered some sleeves and ATX pins on eBay and I started working.
I cut the cables near the connector as it would be easier to remove the pins. When I cut those I put the sleeves around the cables (2 cables per sleeve, as I estimated the length a bit wrong, so the sleeves were just a bit too short). I put heatshrink around the ends at the PSU, put pins on the ends of the wires and put the pins in the connector. When I connected it to the PC it didn't boot. Jiggling a bit with the connector resulted in a split-second boot a few times. I took it out and jumpered the PSU. The PSU fired up but there was a grinding noise for a few seconds, then a pop and a little bit of smoke. Of course I pulled the jumper out immediately.
I really don't get what could've gone wrong. I didn't re-wire anything or whatever, I just put sleeves around everything and put them back in the connector. I'm 100% sure I put every pin in the right socket, and even if I didn't it wouldn't have died when I jumpered it. Right?
I hope any of you can help me at least understand what went wrong.
If you need any more information you can of course ask, you're the one helping me after all

 

[theo2021]

Some pics would be nice , it sounds quite OK. The only thing i could think is that you have put the 24 pins incorrect but you' re 100% sure.
How did you shrink the heat shrink ?
May anything dropped into the PSU?

I cut the cables near the connector

You Mean the sleeve?

 

[blobster21]

From your description, you jumpered 2 pins not meant to meet each other under normal working condition.

are there any overheating traces around atx pins you linked together ?

if you didn't rewire anything, what else could it be anyway ?

 

[Debat0r]

@blobster21 That's exactly my point, where could it have gone wrong? I jumpered the green wire with a neighbouring black wire. I must've done something wrong, since if I didn't I would be playing games on my PC right now
@theo2021 I'm sure the pins are in right, and as I've said, and if that isn't the case it shouldn't matter when I jumper two pins. The only thing I can think of right now is that some labels fell off, so I might not have the exact same wire in the same plug. I have some experience with electronics, and all wires of the same colorare the same voltage and come from the same point, so it shouldn't matter as long as I put a black wire where a black wire is needed etc, which I did. Correct me if I'm a complete moron and this is the reason. I'll upload some pics in a few, as it's quite tedious to do from my phone.
Thanks for you help so far anyways!

 

[Debat0r]

Can't upload anything to imageshack from my phone unfortunately, so a
I'll have to wait until the laptop is available

 

[Debat0r]

Update: when I jumper the green wire to another black wire it only boots for like half a second, but at least it doesn't burn up...