Description and Specs
The OEM power supply for the Alienware Graphics Amplifier (“AGA” ) is Dell Part Number DPS-460DB-13A (for mine at least). It’s 460 Watts, and most appear to be OEM’d by Delta.
There’s no provision on the chassis for a voltage-selection switch, so all models can accept 100VAC to 240VAC.
It also lacks a physical power switch, but it does have indicator LEDs.
Connectors
It has a standard 24-pin ATX connector (Molex Mini-Fit Jr, 39012240) and provides provides two 8-pin PCIe power connectors, but that’s it: it does’t include any disk drive power connectors or P4-12V.
Form Factor and Physical Size
The physical form factor is “SFX PS3” (ATX 3.0 spec, 14.9), sometimes known as “Micro PS3”. This size is also used in a ton of Dell and HP PCs.
The PS3 form factor is problem because the location of the AC connector is different than a “regular” ATX power supply, and so most replacement power supplies won’t properly line up with the cutouts in the AGA chassis.
Finding Replacements
Since it’s predominantly an OEM form factor, you can’t reliably find aftermarket replacements from quality manufacturers. For example, Corsair sells the CX650M but the same SKU is used for both the “normal” ATX and the PS3 variant. You must verify the that the product description says “PS3” form factor, or visually confirm the location of the power connector.
These are sometimes called “Half-Size ATX” too, but that’s not an official name so beware and always check visually before buying. If the power supply has a power switch, it is not going to fit in your AGA.
Your other replacement options include getting a compatible Dell or HP part number, like HU460AM-01, D460AM-03, WC1T4, and FVGCW, or going at the chassis with a hacksaw.
Repair, Don’t Replace
Delta electronics is a quality OEM company so, barring physical damage, it’s worth trying to repair your PSU if you can.
Replacing a dead fan is something adults can do, even with zero experience. You don’t even need to know how to solder: you can get “solder-less butt connectors” from most auto parts stores, and they’ll work just fine.
Now, if the thing simply doesn’t turn on anymore or the output voltages are off, that’s different. In those cases it’s likely the capacitors have failed.
This does require soldering, but it’s a great way to learn how! There are many beginner tutorials on the web, Youtube, and Reddit. After all, you were ready to throw it in the trash anyway, so why not try?