I got a great example today I can post up.

Lady has a high end oven. I go last week and diagnose from the control. I look for Ohms between the contacts going to the elements. The wiring diagram gives you watts, so you use Ohm's law to figure out resistance. You measure for Ohms and check ranges. Well blatantly I got an open line reading on the bake element. I pulled it and replaced it.

I test it and it works fine.

Lady calls me back frantically Saturday. "IT'S NOT WORKING AND I PAID $366 FOR THE REPAIR!!!"

I go out first thing today and with the board out everything works. Put it back together it doesn't work, pull it back out and it works. Funny. Obvious loose connection somewhere

So I remove the board and find a tiny little partially blown resistor, one leg of it is loose and only completes its circuit when gravity is assisting it. For some reason it makes contact when the board is facing up but when the board is sideways and installed in the oven it does not do it's job.

The resistor goes to the cut-off relay, so with the resistor not making contact the main relay does not allow power pass through.

I usually test with the control open so I can get my plugs in there. It ran great when I tested it, after re-install it failed.

So I took the board home with me and plan on repairing it tonight. The board would have cost here $320 just for the part, and she for sure needed the expensive hidden style element I replaced as it was blown. So it would have been a $600 repair for her.

Because of circumstances I'm not going to charge for the repair on the board.
It's a $0.10 part that I have tons of at home.

Her original complaint was that "nothing happened" when she turned it on. She guessed it was the board, and she was right. But the element had a huge burnt out spot. Looks like the two issues were related. My repair guide says to change both the element and the control and charge $727.85 for the repair. That is crazy.

I did err when I found the bad element and assumed that is all that was wrong.

This post was edited on 1/30/17 at 1:48 pm