Hello, I am from Vancouver Island Canada and have similar 3b issues. My amp was turned on while the preamp was turned up and I believe only one channel was hooked up. The result was a blown fuse. Replacement was the same result. I have limited tools and experience but love to do basic troubleshooting. Your reply to the other poster got me excited and begging for more information. I work for a large telecommunications company and have a large collection of spare parts (mostly used) like huge caps, connections, power supplies, heatsinks, transistors, etc. I also have a 3b nrb working fine that I can look at for comparison. Will you please extend the same offer of help?
Thank you, Steve.