sickamps

If its class D and looking at the picture its a switched mode (SMPSU) you will have likely fried it. Generally these power supplies don't fuse before they pop in an incorrect voltage selection, unfortunately as the amp and power supply are on the same board it'll be a whole board change. This kind of overload in our experiences are generally not worth component replacement as it's caused quite a bit of stress. If you have a tester check the white fuse. The main preamp board will likely be fine mind you.

I know its a little old but worth it for people searching the search engines as it is a good resource to see recommendations. We're sickamps in Harlow and used to be the outsource repair for Giggear and many of the other local music shops in Hertford, Harlow and Bishop's Stortford as well as provide many studios in the same area with repairs of mixing desks, speakers, guitar and bass amps and electric pianos and synths. link to our site sorry for the shameless post Chris