Plinius amp repair in Michigan

I have used Plinius SA102 amp with CD-LAD preamp, and recently with M16 preamp which I recently obtained for its phono.
The amp suddenly shut off when I manually changed the input of the preamp from CD to phono. It worked just fine when the input was changed with the remote.
After that, the right channel went completely dead. After that, when I raise the volume at the moderate level, the left channel shuts off. The left channel is still alive though.
The preamp works fine with another power amp I have (much less amp).
So, I need to get the amp serviced. The problem is, the closest Plinius dealer does not repair the amp. I contacted Plinius service in New Zeeland via email for suggestions of any nearby service center, but I've got no response.
I live 100 miles north of Detroit, MI. Can anybody suggest me somebody who can repair Plinius in Michigan? Or maybe in Ohio, Indiana, or Chicago area? I don't want to ship this heavy amp.
Many thanks for your help.