The problem is likely a too large line drop from your power pole transformer. A 200A service doesn't matter - what matters is how far your transformer is from your house. It sounds to me that it is too far (or too many houses on the same one) and you should have your power company check. A multimeter will not help you either because your problem is a transient one. Also, the problem can't be too small wiring.
I had the same problem and I had the power company fix it for free by installing a transformer just for my house. Your amp is shutting down due to simple undervoltage (i.e., overcurrent) because your AC compressor must be a big one. Good luck - you will need to make several calls to get it fixed.
Arthur
I had the same problem and I had the power company fix it for free by installing a transformer just for my house. Your amp is shutting down due to simple undervoltage (i.e., overcurrent) because your AC compressor must be a big one. Good luck - you will need to make several calls to get it fixed.
Arthur