Dreamcast:Replacement Power Supply

The Dreamcast power supply is installed internally, and it can be replaced either by swapping in the same model PSU or a third party replacement. It's generally recommended to repair the factory PSU with new capacitors in the event they are leaking/blown and continuing to use it instead of a third party one, or just use a replacement power supply of the same model from another Dreamcast.

Capacitor Kits
There are eight revisions of the Dreamcast power supply, and listed below are capacitor kits for each one:

Third party replacements
In the event that the factory power supply cannot be replaced or repaired, or you need a region specific replacement, there are third party replacements available that can be swapped in instead. All of these are powered from an external 12v adapter, which may be sold separately depending on resellers.

DreamPort (4x Bluetooth controller port + PSU variant also available here)

PicoDreamcast

ReDream PSU