Hi LouLomis, I read your post. As someone who took up analog electronics repair as a hobby a few years a go, I can tell you it is extremely challenging repairing 40+ year old electronics, and you should make sure you have everything in place before you begin. This includes having quality repair and diagnostic equipment, including a good soldering iron, de-soldering tools (pump and/or wick), a high quality multimeter and oscilloscope. Next, make sure you understand how to read electronic schematics.

For the Electric Mistress, we are all fortunate for Ralph’s website which provide schematics of all the different versions, as well as photos. These should be sufficient for you to answer question #1, even though I must confess that I’m not quite sure of what you mean by “pins” and “chips”. If by chip you mean the IC, I would make sure you identify which part it is specifically (i.e., 4558) so that other people understand.

For me, the most puzzling comment is when you measured the resistance of the two prong cord. First off, I have no idea where these measurements were recorded. But more importantly, this is a meaningless measurement. Outside of checking to make sure your have the right resistor in place, resistance is rarely measure when troubleshooting. You want to focus on voltage. The prongs deliver 120V (or 240V) of alternating voltage to the step down transformer, which then gives off 32 V that passes through the power diodes that feeds 18V (half the wave) into the linear voltage regulator which gives the end result of 15V of steady DC voltage which powers the circuit. My experience is that these linear voltage regulators are commonly fried and need to be replaced, especially after all these years.

Regardless, you need to use your multimeter to look at voltages throughout the circuit. There are so many possibilities that can cause you to get no sound.

This is a common problem. I suggest that someone with 3D printing capabilities make these for the Vintage EHX community. I know many people would pay for these, so it’s a great business opportunity.

The plastic D shaft is long discontinued