I also measured the transistor EBC and the collector of Q745 is at 0.74V vs 3.1V shown on the schematic. But, when I solder it into the PCB, I measure 34VDC at the relay input with the DMM (the schematic says it should be 23VDC). On the scope, it is half-wave rectified and measures slightly less than +40VAC peak as it should, so diode is working. I de-soldered the cathode lead of the rectifier diode Q754 and measured the voltage. Measured AC input to the board at J705 is 30VAC measured with a Fluke DMM, 80VAC p-p on a scope. To debug, I tried replacing relay L703 with an Omron MY4, replaced diodes Q754 & Q746, and transistors Q743, Q744, & Q745, one at a time. I think I have a voltage problem at the speaker relay (L703) coil. My question is: my speaker relay is getting hot to the touch. Recently I bought a used 2252b in working condition from Goodwill and recapped the electrolytic capacitors on the P700 Main Amp and Power Supply PCB, and main filter caps. I had a new Marantz 2230 when I was in college and sold it long ago. I have been reading all of your helpful responses for many years, but finally joined.
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