Hi Tony and welcome to thecarversite.com. Glad you found us.
We do have a few schematics for the Sunfire Cinema Grand. Unless something has changed, you should be able to download the files. I wish I could offer some pointers as to where to troubleshoot your amp, but I'm in no way qualified.
The files are at this link:
https://thecarversite.com/carvermanuals/
There will be a box in the page that looks something like an Excel spreadsheet. Along the bottom of the box you will see some more links, and one of them is Sunfire. Click on that and it will load the box with the manuals and schematics that we have.
I hope that helps.