Product review (5 stars): Works fine but didn't fix the problem.
Ordered this but think it wasn't the door lock though everything seemed to point to that. Noticed that with a little added pressure applied to the "start" button, the washer would start without a lot of delay. I believe the intermittent start problem with my Duet washer WFW9400SW02 is the actual surface mounted circuit board switch under the "start" button. There are a bunch of these temporary on buttons mounted on the control circuit board(s) under the plastic control panel on the top of the washer. This start button gets the majority of the use because you have to push and "hold" the button til the washer starts. Think the interior contacts inside the switch just get worn out (Or a lose or cold solder connection). The picture shows the buttons on the middle board. The one circled in red is the "start" switch. Contacts are closed only while you press & hold the "start" button. The top one to the left is the "power on" button. The two bottom ones I believe are the "lock" on the left and the one to the right bottom is the "Cancel/Pause". If you could find the switch model number bet you could replace (solder) the switch for a few pennies and your labor to get the board out of there. I DO NOT RECOMMEND ANYONE TRYING THIS. Its just a hunch!!! Going to pull the new latch lock and keep for a backup and put the old one back in.