As a follow up. I see where there are solder joints on the front frame for the blue wire and on the back frame for the black wire. It appears that the red wire goes between the frames. Any idea on what this connects to?
All ESL panels require three power connections:
The two wires connecting to the front & rear stators are from a transformer that steps up your amplifiers AC output to the much higher voltage needed to drive the ESL.
It's important that these wires do not have missing or cracked insulation that might allow exposed bare wire strands to overhang the stator edges, as this could result in damaging arcing to the opposite stator or wire.
There is huge electrical potential (thousands of volts) between all three wires, and you don't want any bare wire strands touching or even close to each other because that much potential can throw a spark across a 3/8" gap.
If you see any bare strands overhanging the stator edge, either replace the faulty wire and connection or at least apply some RTV silicone around the exposed wire strands, as insulation.
The third [red] wire comes from a high-voltage DC bias supply, and [probably] connects to a copper foil periphery charge ring sitting atop the diaphragm, about 1/2" in from the panel edge.
The charge ring extends around the periphery of the panel and conducts the DC biasing voltage onto the diaphragm.
I was going to add that you must be very careful not to pull on this bias supply wire (the red one), as its connection to the foil charge ring is fragile and easily broken--- but I see that someone has already pulled that wire out :-(
Don't despair just yet... there may be an easy fix:
I'm not not sure if all ML models use a full-periphery foil charge ring but that would be my guess.
If so; that red wire would have been connected to a periphery charge ring that sits atop the diaphragm, about 1/2" in from the panel edge.
Here's what I suggest:
You will need a thin, flat copper probe 3/4" to 1" long, to insert between the stators and contact the charge ring. It must be thick enough to resist bending but no thicker than necessary, and its edges must be smooth so it inserts smoothly without tearing the diaphragm.
You could easily make the perfect probe by hammering flat a piece of 10 gauge or 12 gauge single strand electrical wire.
Solder your bias supply wire onto one of end of the probe but splay the wire strands to make the flattest possible solder joint (you don't want a fat gob of solder that could impinge on and arc to a stator).
Also, you might want to wrap the soldered end with a layer of electrical tape to isolate it from the stators. For sure you want to insulate any portion of the probe that protrudes after you've inserted it into the panel.
The charge ring will be on the top surface of the diaphragm, so you will need to insert this probe between the stator spacers and on top of the diaphragm. The "top" surface faces the front stator.
You don't necessarily have to insert the probe in the exact same place that the wire pulled out from-- if there is a periphery charge ring, then anywhere along the periphery will suffice.
You merely need the probe to touch the charge ring to make an electrical connection. It's not as robust as a soldered connection but functional, and the panel should then play.
Once you have the connection, you will want to fold the wire against the stator edge and over-wrap it to the panel with tape so that it doesn't pull out easily.
Good luck with it!
