I checked again and with the lead on and power on I get 26v at pin 5 and 0 at pin 4....Snip
Not sure how you're getting the two different readings as there is only one test, which should give you just a single result.
Try this.
With power on and connector attached to J1, probe the red lead to pin 4 and at the same time the black lead to pin 5.
Meter set to AC volts should give you a single reading in volts AC. (See diagram below)
No probe should be connected to any ground.
With connector off and power on 0 at both....Snip
This connector brings power to the board, so a 0 value would be expected when it is not connected.
