If it is the amps then is there anything that can be done to fix them, or is the unit scrap?
Most certainly one or more of your SoundBridge's three amps have failed. Pete in the UK (user name g0pkh
in these forums) should still have replacement amp boards or speaker units, you can contact him by sending a PM
You will find an illustrated guide to disasembling the R1000 here
Replacing the front speaker units is quite simple following these instructions