What is a MOSFET?
It's a Metal Oxide Semiconductor Field Effect Transistor. They work by black magic, just like a processor.
Why the hell did you want to replace them you freak!?
The old ones wouldn't do what I wanted them to do. They were too hot and not beefy enough. OK!?
What I did
I went to an electronics forum, and grovelled until they decided to help me. They then said that I needed a FET with high amperage and low RDS(on). I don't fully understand the rest...
After that, I went to the only place I know that sells weird-ass electronics - eBay! I found some IRL2203N's (catchy name eh?). I wanted some Hexfets because the name sounds cool.
When they arrived, I became very nervous about the whole thing, and then proceeded to cut the legs off of the old FETs. This is because, with a normal soldering iron at least, you CANNOT REMOVE THEM. This caused great pain. Anywho, I continued to then fully remove the old legs by desoldering them. This left a nice patch of PCB to solder the legs of the new FETs on to.
I then enlisted the help/emotional support of moistmule, and together we soldered two legs of the new FETs onto those nice patches, hooked the board up to a PSU/monitor etc. switched it on and.... nothing. Arse.
Then it got hard.
I didn't realise that you have to have 3 connections to the FETs. I know... I must have had a brain fart. Transistors always have 3 legs! Durrr! 3 connections you idiot!! 3!!!! I was thrown because the FETs actually use that little tab to conduct electricity.. apparently it's the output... ARGH!!
After crying for around 12 hours at my own stupidity, I tried to solder a piece of wire from the tab on the new FETs to the tab on the old FETs... seems like a reasonable plan right? WRONG! Just to spite me, the tabs on the old ones seem to be allergic to solder and it just would not stick to it, no matter how much we scratched them up. Soooo.... moist came up with the idea of basically destroying the pins on the new FETs and bending them into shape so as the ones at the side can touch the nice blank soldery parts on the board and the middle pins on both the old and new FETs would touch each other. This took a fair amount of time. After around 5 hours or so, the FETs were finally in the right place (with the worst soldering job you will ever see).
And one more, just for luck ;)
Unexpectantly, I hooked it back up to the required stuff, switched it on and waited for nothing to happen. Alas, the poor thing actually booted! W00tness! After the excitement had worn off I finally managed to sit down and test these new piece of equipment. I could get this SL6JT (Google it) to sit in the BIOS at 1.82GHz quite happily. All was looking good.
So I rebuilt this machine, and tried to boot at 1.82GHz. Got through POST, but as soon as it even tried to load windows the thing hung. Bugger. So I knocked it back down to 1.73GHz and it loaded no problem.
I used to be able to run this thing at 1.73GHz (1.7v) with the old FETs, but they had to be actively cooled. I am now able to run the same settings without any cooling on them, although they are too hot to touch. Maybe they just handle heat better!?
Anyway, advice to someone thinking of doing this - DON'T! It's not worth it. I thought it would be great, but it has hardly made a difference. I cannot overclock any further.
Good fun though! :)
A stupid note
Whilst attempting to solder, moistmule let the soldering iron rest on my CPU slot... thanks for that moist!
Mmmmm... but its still works, so I don't care :)