Marantz Audio Amplifier Model 1030 , Noise problem (audio inside) .

Wow, an old Marantz! Cool!

I vaguely remember this model number - I wonder if it's at all similar to the old 1120.

At any rate, I remember we had a devil of a time finding an intermittent noise problem in one of these units (might've been a 1030, or 1120). Everyone was stumped for weeks (including Marantz tech support) until one day we noticed that the double-sided circuit board had these two large rivets near the top edge, with no apparent function.

Turned out that these were a "connection" from one side of the PCB to the other. There was a large amount of old flux around them and they had become very intermittent. We cleaned them well, removed old solder, resoldered them (you need a big iron or a gun to get them hot enough) and that fixed it.

Good luck.