The "Normal" light is flashing. As a result the unit will not run thru a normal cycle - it may run for a while but when the lights starts flashing it stops. I have run thru the "Heated Dry-Normal-Heated Dry-Normal" reset process with varying control panel responses - sometimes, upon completion, the "Cancel/Drain" light will come on and unit runs for a short time (presumably draining any water left in the bottom; other times, upon completion, the unit will light up like a christmas tree with all the lights coming on for a short time and then all turning off for a few minutes and then "Normal" light will commence to blink again; other times other lights may come on and then go off only to have Normal light flashing again after short delay - in all cases, however, I can normally go thru the process whereupon the Normal light is off for a while. I have also tried "Normal-Pots/Pans-Normal-Pots/Pans" with same results (eventually Normal will flash again). I have also tried running thru the cycle and then opening and closing the door at the end - same results. I'm stymied - I initially thought, after all the lights came on that the reset process must have worked but eventually light started flashing again. One other avenue I have questioned is a defective/stuck door latch. In looking at the assembly from the outside (I don't know how to open up the latch area) and it seems that the latch may not be fully engaged when the door is closed - it seems to feel closed but I'm not sure about the latch mechanism.

I read that there is a tech guide that spells out diagnostic checks under the front panel of the unit but I can't see how to access it.

I'm at a point now wondering 1) the control panel is defective, 2) could it be the latch, and 3), if any of these, how do I open up the back and get to the panel - in that the control panel area doesn't have its own access, the only way I can see is to remove all the screws on the back of the door.

One more thing, I also read that the "ribbon cable"ay need cleaning. If so, is this something that I should be able to do (not being a technician) w/o too much trouble?

Complete model number DU1145XTPQ7 (lsuffix designates that it's the white unit)

Is replacing the control panel a challenging/difficult procedure?

I assume that it would be OK to trip the circuit breaker as an alternative to unplugging the unit, right. What is the connection between the control panel and dishwasher itself?

Simon - Curious as to your rationale for pin-pointing the flashing "Normal" problem as most likely being in the control panel not the control circuit board. Is there any simple check I could do to verify this?
Don