Thanks for noticing that we all work together (as Jeff Liebermann would know, we stick together in the mountains).
I called the "circuit board medics" at 800-547-2049 last week who said that an F28 on the Whirlpool duet sport washer is almost always a bad motor control board.
This was before I had taken out the MCU and found it burnt, so, they're right. In hindsight, if I had only known that, I wouldn't have removed both the CCU and the EMI filter (I broke a wire on the CCU trying to get it out, for example).
So, to help others.
- If you get an F28 on the Whirlpool duet sport WFW8410SW, it's almost always the motor control board.
- Wiggle the blue wires on both the motor control board and the CCU, but if that doesn't solve the problem, then you have to remove the motor control board.
- To remove the MCU, you have to remove the 16 quarter-inch hexhead screws holding the back plate in place.
- It's advised to also remove the lower cross brace (two more screws).
- Some people remove the top of the shock absorber but I left it in place.
- Then you have to cut or dig out the 4 tie wraps holding the harnesses to the MCU plastic covering.
- Then you have to be a genius or a magician to put a screwdriver under the MCU white box and pry it up and then slide the MCU toward the front of the washer, to get it to release its grip.
- Then you remove all the wire connections & pull it out from the bottom of the Whirlpool duet sport washer.
- Once you pry open (and probably break) the crappy plastic (they really use really really really brittle plastic), you will see the scorch marks as shown below. formatting link
At this point, you put the MMU back in its plastic case, and you remove the CCU (if desired) and you ship both of those boards to the rebuilders at "Circuit Board Medics" 800-547-2049x3) at your cost. They told me that USPS is the least responsible, so use UPS or Fedex.
Exclusive of your costs to ship to them, the charges are: A. Exchange rebuilt MCU = $175 ($160 + $15 shipping + $100 core charge) B. Rebuild your MCU = $145 ($130 + $15 return shipping)
They give you a 1-year warranty and they will test both boards for free, just in case my totally burned out MCU isn't the real problem.
Here's a picture of my CCU, which seems to be in OK shape:
Unless I find a better deal than ~$150, I think I'll have them rebuild my board. A brand-new washer is only four or five times that at about $600 to $800, so, it's an expensive enough repair to wonder if I should just buy a new washer instead.
Nonetheless, I don't have much money lately (being retired is costing me more than I thought, especially with two families living under the same household now, with my sister and her kids living with me), so, I will just look to see if I can find a new board for around that same price.
Otherwise, I'd suggest the rebuilders as they seem competent.