DELL Server Power Supply AA233300 repair

These power supplies are available under a number of different model numbers / brands. However they are all really the same (only minor mechnical outside differences). This is great for us as it means that we can use them to repair other models if needed.

The DS550-3

The DS550-3 is the actual manufacturers model number for this supply. It was manufactuered by Emerson, However it appears that the same supply is also manufactured by Artesyn Embedded Technologies.


To begin the dis-assembly of the power supple, it begisn nice and easy. Just 4 phillips screws highlighted below.

Outside of the enclosure with screws circled

Easy to remove screws

After removing the screws, dis-assembly is nice and easy, the top part of the power supply (label side in my case) will hinge up and out of the way.

The hinge for the cover simply slides out revealing the power supply in all its glory

Cover removed

Cover removed

The suspects are found

As with every power supply repair that can be found.. Anywhere, the output filtering caps are first to fail.



These caps are rated at 1000uF @ 16V, and there are three of them crammed in down there. All three of these are used to filter the output 12V rail from the power supply, one filters the output rail before the current shunt and then the other two filter the final output voltage.

To remove the main circuit board from the unit is quite easy, just unplugging two cables and then removing 4 screws total from the unit.


Screws 1 & 2 and cable 1


Screw 3


Screws 4 and cable 2

And now comes the easy part, just desolder and replace the caps.