Thanks. I do have the input and output bias adjusted to spec ranges. The amp recently was recapped and sounds great.
On a second D-150A SII in for repairs; I've recapped it and replaced blown output transistors on channel 1. I've measured and adjusted input/output bias to spec, however on turn on channel one IOC doesn't flash nor go on briefly post turn off like channel two does. Any suggestion where to check ? should I assume when the output blew it took out part of the IOC?