Broken ProTrack leg, then found interesting buildup.

[Al1234]

I broke the front leg with 1 finger, not On purpose
Due to loose scrws under the main board I had to get them out before turning it back on.
Removed almost everything. Then found something very interesting in the back side of the main board. A bridge of dirt from channel A to common. See picture.
I do have intermittent overvoltage massages on this unit. After a good cleanup, we will see if it happens again.

[jvthorsley]

That amount of dust could give confusing results on high resistance ranges especially in a humid atmosphere!

[Al1234]

Yes I am sure you are correct.