[JackStraw]

I'm looking for some advice... I have an Acurus DIA-100 Mk II Integrated that's maybe 10 years old. It seems to be functioning perfectly fine, but the green LED on the power switch seems to either be going bad or getting intermittent power. It dims while the unit is powered on, varying brightness from OFF to full brightness. There is no change in output volume while this is taking place, though. I'm considering selling the unit, but I don't want to get a bunch of complaints about the unit because of this...

Can anybody tell me what it might be from that description?

[audioengr]

This is usually just taken off a DC supply voltage.  If the amps sounds fine, it may just be a connector.  Open it up (unplug it first) and check the wiring to the LED.  If it is entirely on a circuit board, then check the resistor and traces that feed the LED.