I know this is an old thread, but registered to reply here to hopefully help other people who are googling this.
If you have tested the heater element using a meter (approx. 30 ohm is normal - mine was around 26) and it is within acceptable normal range, your PCB will probably be at fault. The reason why the previous poster Scottewing may have blown a second PCB is because when mine stopped heating up, I traced the wires back to the PCB and found the main wire going from PCB to heater element connector to have BEEN SLICED in half completely by the sharp edge of the metal door. These wires are supposed to be protected by a plastic enclosure which has disintegrated over the years. The wire would ideally need renewing. However, because there is plenty of it, I pulled the wire through so that I could solder join and heat shrink wrap it together, well away from the flexing hinge area. I then of course needed a new plastic protector from Whirlpool for £10.99...
http://www.4whirlpool.co.uk/dishwas...t.pl?pid=822181&path=600157&model_ref=2601413
My thinking regarding Scottewing's problem is that this live wire may have been touching metal (earth) and possibly blowing PCB's...
Hope this helps someone.
HOWEVER - please make sure you DO NOT OPERATE the machine again unless you have correctly fitted a new plastic protector and IF IN DOUBT - either renew the whole wiring harness (though I think you'll find this not economical) OR SEEK PROFESSIONAL SUPPORT. If you botch this repair, you could have a VERY dangerous dishwasher in your kitchen...
If you choose to replace a section of the wiring harness, YOU WOULD NEED TO USE THE SAME THICKNESS/GAUGE WIRE (you will need knowledge of SWG - standard wire gauge).
Important note - twisting wires and using insulation tape is definitely not acceptable. I chose to solder and use heat shrink wrap insulation.
** PLEASE NOTE - I AM NOT MAKING ANY RECOMMENDATIONS REGARDING REPAIR METHODS HERE (though I do recommend what is NOT acceptable practice) - AND AM MERELY POINTING OUT THE METHOD I USED TO REPAIR MY MACHINE AND HIGHLIGHTING POSSIBLE OPTIONS - IT IS UP TO YOU WHAT YOU DO AND I DO NOT ACCEPT RESPONSIBILITY FOR ANYONE EFFECTING THEIR OWN REPAIR BASED UPON THIS INFORMATION **