Before I get started I'd like to first discourage everyone from opening their psu. Simply send it back to MS if it's defective. Opening your psu can kill you. You can damage your psu. I urge you not to take your psu apart and reading any further means that you agree that I am not responsible for what YOU do while taking YOUR psu apart. You have been warned.
You'll need some tools before opening your psu.
#1 philips screwdriver
#2 philips screwdriver
Arctic Silver 5 thermal compound
Step 1. In order to attempt to discharge the capacitors in the psu, turn your xbox on and leave it at the dash. Next simply unplug the power chord from the wall. You will notice your led on your psu stays on for a few seconds and then goes out. Now unplug everything from your power brick and take it to your work area.
2. Pry the plastic feet out. (WARNING: I haven't found a way to get them out without destroying them) Next, the screws are super-glued in. You'll need to take your soldering pencil and heat the screws. You will smell the smell of hot super-glue and if you're not careful it will sting your eyes. Once you hear the squeeking sound of the glue boiling, quickly grab your #2 philips and unscrew that screw.
3. After you get all 4 screws out take the housing off of the unit. Now you'll notice a big metal sheild covering the components and the psu won't come out of the other housing. [Do not take this metal sheild off. The only thing it is covering is the leads (solder pads)on the bottom of the unit]The circuit board is actually held in place with compound. Gently pull the pcb away from the compound and do not bend the pcb. It is really stuck on there. You are pulling away the pcb from the main heatsink and air duct. Detach the fan leads.
4. Clean the old thermal compound off as you go. (Only do this if you plan to upgrade to AS5) It makes it much easier. Next remove the heat transfer plate that is on the side the chord and led are on. The screw (1 screw.) The other screw is holding the heat plate to the transistor. Don't loosen it. If anything tighten it.
5. Now on the top assembly (the one with the fan)unscrew the small screws holding the metal down with your #1 screwdriver. The metal will come away to reveal a heatsink on top and a duct that the fan draws air through.
6. If you'd like to increase your fan's airflow efficiency cut the holes out so that you have large slots on both ends of the duct
7. Now that you have all the metal pieces off and cleaned. Clean them with isopropyl alcohol and a q-tip and then apply your AS5 between all the heat spreaders and transfer plates where they make contact. Screw down all the screws so you get good contact. (this means where the transistors touch the actual heat plates. This means where the heat plates touch each other and also where the heat duct touches the heatsink.)You want excellent contact area (thermal compound) and excellent contact pressure (screws). You also want increased airflow. (Slots where holes were). This should make your psu much more efficient as far as how it removes heat from itself.
8. Follow the steps on disassembly in reverse to put it back together. Make sure you screw your case screws down tight as well because that's how your psu heat plates touch the heat duct.
On an interesting note, there is a potentiometer on the fan control pcb. I have not taken meaurements but I just wonder if that control the fan speed.
Pics will come this evening. I have taken them but I am at work.
Edited by BCfosheezy, 16 December 2005 - 08:46 PM.