I have a plb-amp8 (actually four of them) which after years of not using, I have now discovered I can use without Phast controller. So, I turned them on disconnected from phast link to test out. Two of the units powered-up fine, allowed me to run them without Phast.... but only for about 20 minutes. When I cycled power, they both stopped working... asif a fuse hase blown. I had not terminated the phast link ports... so I did that. Checked the two external fuses and teh one internal and none of them checks out as "open" so I assume they still work. But the amp gets no power... any ideas?