I also had this problem with my Whirlpool Quiet Partner II. Mine also suffered from the pesky issue where the thermal cut off (TCO) fuse inside the control board compartment trips halfway through the cycle cutting power to the dishwasher and all that for no apparent reason.
The first issue as very correctly Mayer above has already explained is either a control board or a front console malfunction. The method suggested for troubleshooting and identifying the problem is very sound.
My experience is that if the control board fails first that's usually one or two bad capacitors that can be easily replaced. However a capacitor will fail because the ambient operating temperature is higher than what it should be. This is where the TCO comes in. If the operating temperature inside the control compartment is too high the fuse will trip and stops damage to the control board. But sometimes the damage has already been done.
In my opinion the front console could also be the culprit if there are any stuck buttons or even if the foil inside the buttons gets corroded it will produce spurious connections/voltages which can damage the control board.
In my case I discovered it was both: I had a bad front console AND a damaged control board. If you look around long and diligently enough you will be able to find replacement parts. Do not buy brand new OEM directly from Whirlpool they're too expensive go for refurbished or used from Amazon or ebay, etc. In my case I was able to find both parts spending less than $200, which was worth it, since my dishwasher has been working flawlessly for the past 3-4 years now.
Final note, if you are experiencing the TCO fuse blowing up all the time, there is a working safe solution for that as well, feel free to email me at R1100RA(at)gMail(dot)com and I will send you very detailed instructions at no cost.