From what I've read MPC declared bankruptcy last year which makes finding those parts somewhat difficult. However, ECS manufactured MPC and its associated parts. Therefore, if you visit their website, choose your location, browse to their support section, then contact them (via email or phone) they will be able to get you information on the power unit and, possibly, where to purchase it.
http://www.ecs.com.tw/ - ECS Website
NOTE: From my initial research, the power cords for the MPC 414 does not seem to be inexpensive.
Answers & Comments
From what I've read MPC declared bankruptcy last year which makes finding those parts somewhat difficult. However, ECS manufactured MPC and its associated parts. Therefore, if you visit their website, choose your location, browse to their support section, then contact them (via email or phone) they will be able to get you information on the power unit and, possibly, where to purchase it.
http://www.ecs.com.tw/ - ECS Website
NOTE: From my initial research, the power cords for the MPC 414 does not seem to be inexpensive.
Let us know how things turn out.