First a blown power supply can mean stuff further down has died too so if you can test out the equipment in another machine.
It seems Sony have pulled their usual proprietary parts trick which I intensely dislike although I suppose it does give me some work on occasion.
Paying silly money for a power supply is not on, especially when a replacement machine of the same specs would be around that in price (to save others search:
http://www.shopping.com/xPF-VAIO-VGC-RA820G )
Brackets are easy enough, I usually use oblongs of sheet metal and drill holes for customs supplies. I have tangled with these sort of things in the past so check there is no switch anywhere in the case to prevent this from working.
The trouble is you now need to find a pin out for the psu and sony manuals are as helpful as ever.
I assume you are not overly familiar with electrical engineering or I would suggest you adapt another one so you need to find enough info to for a shop.
Now comes the hard part, reverse engineering a broken item. Ultimately you will need the dead supply unless you want to make connectors.
First a search.
http://www.agoraquest.com/viewtopic.php?to...rd2=electronics
There is a now dead link on the page to something that might be useful but there is also a post.
Later searching says sony proprietary stuff is shared between sony systems which is nice.
http://www.computing.net/answers/hardware/...ctor/46350.html
The people that make the supply are delta but they are not going to have anything:
http://www.deltaww.com/
Now to the problem at hand:
It is usually a transformer or coils that blow rather than anything electronic (on the other hand if there is no magic smoke it is usually a loose connection) which is easy enough to bypass so if you get another source in there you can determine a pin out (you could trace manually but it gets harder and voltages are a bit harder to figure out). From that page above it seems you main problem is the custom 3 pin supply and the fact some voltages are checked by the system (ostensibly for reasons of making sure it is all good but I would sooner read a check you have not replaced it). 3 wires usually means power, neutral and ground. They said something about the info being there on the supply/wires/board so hopefully you can do that.
Voltages where it matters appear to be normal 5V so you should get away without resistors, zener diodes or further transformers (others reading yes people are using transformers for low voltages again).