[Richard]

Hmmm.

Here is some data I collected from the two fan motor spares I carry. I don’t know which is evap or condenser.

MTR 1

W - R. Lo. 8.1
W - B. Hi. 4.1
R - B. 4.1


MTR 2 (this is a three speed MTR)

W - R 7.5
W - B 3.3
W- Blu 6.1

At the next opportunity, I would test all the start caps for the fan motors. The breaker trip, and the heat that caused the burn look like a direct short to me. And I am going to pull the other board for a look see.

I would also test all the hot legs to ground to check for a short somewhere else. Check the leads from the board to the external relays

As far as the bad joint. It could be vibration. It could be the torque applied to tighten the screws, after all the solder joint bears the force of tightening the screws. It could damage from before the relays were applied. The joint you pictured looks more like melted solder than a solder fracture to my eye. I base that on the rounded edges, but that is speculation.

I saw pictures of the board that Newell first had made, and those pictures are different than the board you pictured. Not saying that is bad, just that is not the 1st board that Newell had made.