Maytag mdbh945aww quiet series 200 dishwasher. can't get it to turn on. Any suggestions.

Check the door switch.

Have you tried tighten the spray arms? They may have come lose at the fittings so need to be tightened up. You can normally tighten them with your hand. Take any traps/filters out of the dishwasher and clean them.
You may find answers here: https://www.maytag.com

Find your circuit breaker for your dishwasher and turn it off for 3-5 minutes. Turn it back on, then turn on your dishwasher. If this works, after the complete cycle of your dishwasher, you have to turn it off manually by pressing "on" botton then press it 1 more time to cancel; this will turn off. The defect is, probably the moisture built up in the control board causing it to ground some of the connections. Suggestion for the manufacturer, insulate the control board to prevent absorbing moisture.

Hi,

Here is a tip that will help you with how to clean that dishwasher up and get it smelling good again...

Dishwasher Maintenance
heatman101

press the heated button for 3seconds

We had the same issue with our Maytag quiet series 200 dishwasher. The Start/cancel button would not work all the time. We ended up removing the front panel from the machine and on the backside of the panel there is a plastic ultra thin ribbon cable that runs from the computer box to the push button control panel. We wiggled the ribbon cable and the start button began to work, but only if the ribbon cable was held in a certain position. So we super glued the cable in that position and it's been working consistently now.

Upon closer inspection the ribbon cable appeared to have 3 or 4 very tiny dark spots on the wires.
That would indicate to me that somehow moisture slowly eroded the tiny wires and bending the cable made the connections touch again, but for how long it will work like this is anyone's guess.
Also, it appears that the ribbon cable is permanently attached to the push button control panel. So you can't replace the ribbon cable itself without buying the hole front panel.

Hold down the heated-dry button for 3 seconds and the light will clear.

Sounds like you have a bad Control Board

http://www.partstore.com/Part/Maytag/Maytag/MDB6600AWW/Maytag/Maytag/99003160/New.aspx

But with the price it cost, you might be better off buying a new dishwasher, preferably a different brand, cause that washer has some bad reviews

under the unit where the water line connects,this is where the filters are.disconnect the water line take the fitting off that the line was hooked to,screen is there under fitting.

MY DISHWASHER KEEPS RUNNING, IT IS A WHIRLPOOL GOLD QUIET PARTNER IV