I used Google Search (Mark Levinson Repairs) and found the following sites for your review:
http://www.highendaudiorepair.com/
http://www.stereorepair.net/highend.htm
http://www.marklevinson.com/support/warranty.asp
The first 2 are independent companies and the third one is Mark Levinson. I suggest you contact all 3 to get estimated prices and time to repair. Hope this helps. cheers..