Sounds like you've done your homework, ive basically came up with the ame results trying to get parts as you did. Im not an electronic tech but have some basic knowledge of testing and repairing electronics, self taught. Im not sure what you mean by rail voltage, how do you check the rail voltage and excess loading. I purchased this amp for $250.00 as a non-working amp, it definately has cosmetic issues but the internals look very good. The amp is only valuable to me if I can repair it if I tack on another $300.00 plus shipping to have it repaired it would be a total loss thank you again for all your help.
I have never worked on a Carver, and actually would never buy one. They are prone to trouble and don't make old bones. I understand from others and going around the Internet, that those amps are very difficult to trouble shoot.
The rail voltages are the voltages to the amp boards. As well as having a magnetic shunt power transformer, the amps are class H. These H amps give more trouble and are far harder to trouble shoot than other topographies. The rail voltage switches according to power demands. The magnetic shunt and this class H switching rail voltage allowed a sleight of hand to make a small power supply and claim high power output. However the Carver is not high powered when tested with a continuous sine wave, or continuous power.
The rosy specs are predicated on the dynamic nature of music. I have a feeling that this modern affliction of pop music with highly compressed dynamic range as contributed as much as anything to making the Carvers bite the dust.
If you are serious about fixing that amp you will need a circuit diagram, and a signal generator FET VOM, and a dual channel scope at the minimum. You will have to read up on a lot of circuit theory. From what you have posted so far, it seems very unlikely you have the skills to fix that amp. If you had, you would still very likely get stumped for lack of parts. Working on most other amps you would be unlikely to get defeated for lack of parts.
I suspect that there is a circuit or component somewhere that has failed and is drawing far too much current. Those amps apparently have a bunch of ballast resistors that run too hot anyway, and can be a root cause for other problems. I think when you switch on the lights are bright and and as the caps charge, there is a circuit somewhere that as it turns on, starts to draw far too much current, the lights dim and the supply goes into a current limiting mode to avoid it smoking.
Be very careful about obtaining equipment that does not work. That amp was not worth $250, it was worth nothing, or very close to it. Even of you had got that amp for nothing I would be telling you that it was not worth the $300 and shipping to fix it. There is an old adage, that says "if it was junk new, it will still be junk after you fix it."
For the cost of fixing that amp and shipping you could have bought yourself a very nice used Quad 405 2 on eBay working. That is ten times the amp the Carver ever was. You could have also bought yourself a
pro amp, for less than your boat anchor.
So you will have to be more careful and circumspect in future. Never give much or anything for gear that does not work. Carefully asses your skill and knowledge, and honestly rate the chances of you fixing it. I'm afraid you have paid $250 for your education so far.
