I got my shipment of the new brush (actually I ordered 3 in case of future failures) from New Zealand.  3 days door-to-door.  Not bad.

The assembly before starting.  I had already desoldered and removed the wire from the center pad.

Now, this step threw me off...  The instructions for replacing the brushes say to curl the lead 3 times around a small screwdriver.  That seemed so specific that I assumed that was an essential part of the finished assembly.  So, I threaded the lead up the channel and through the hole and soldered it with that curl in place.  Turns out that's not how it's supposed to be.  The instructions actually say, in the next step, to pull it taut.  But, my brain kind of skipped that because of the previous instructions to curl it.  After it was already soldered in and partially assembled, it dawned on me that that had to be wrong (because the brush was easily falling out).  So, I desoldered it again and did it without the curling.  Now it looked like the other 2 brushes.  I've asked Airmaster support why that instruction is there, but haven't heard back yet (they wanted feedback on the instructions).

This photo was taken when the curl was still there...

Soldered in place.

Assembled and ready to be put back on top of the sliprings.  You have to compress the brushes into the assembly nearly all the way to get it on top of the sliprings and attached to the gearbox.  Tricky maneuver...

On my last couple of flights, I saw a failure indication on the Airmaster prop controller.  3 Flashing red lights, which means there's an open circuit to the prop.  It was intermittent, but I grounded the plane until it was figured out.

First I checked the sliprings behind the gearbox on which the triple carbon brushes ride.  They seemed fairly smudgy so I cleaned them gently with a Scotchbrite pad.  Nope, that didn't make a difference.

Then I looked behind the panel on both sides to look for any loose wires and didn't find anything (I was also searching for loose grounds that might be related to the audio static).

Since nothing turned up it was time to take a look at the brush assembly since I've heard of others having issues with those.

As soon as I loosened the assembly and angled it up.... The center one just fell out.  A broken wire, which apparently others have seen.  Time to get a replacement (actually ordering 3 for future failures...) shipped ASAP from New Zealand.

A photo I took at 6B6 this past week right before an EAA Chapter meeting.

A bit earlier than the previous photo.

Before a recent night flight.  Flying into 6B6 at night is intense... A tiny runway barely lit surrounded by pitch blackness, which includes tall trees and hills.  Good thing I have insanely bright landing and taxi lights that illuminate the trees a bit before I get to them.

Those tiny small lights you see - that's what outlines the runway.