Agreed: Rich, what I ment when I told you to check for ripple, would be "big" ripple, which would be an indication of the filter caps having dried out - not all that likely, but worth checking. The input to the regulators should not drop below 7v under load. I always scope supplies under initial load tests - You never know what odd things you might see... Regards, Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.parse.com/~ddunfield/museum/index.html