Master Reg lays out the drill:

Checking keyswitch contacts:

Unplug dishwasher or disconnect power.

Remove connector P1 from the control board.

Using the table below,

http://appliantology...-ii-dishwasher/

measure the resistance across the switch when the key is pressed.

NOTE: The meter must be connected with the proper polarity.

This test will not work on models with a “touch sensor” type user interface.

The resistance reading should go from infinity (open circuit) with the key open

down to a readable Ω level with the key pressed.

The level may be different depending on your meter, since there is a diode in the circuit.

If available, you could use the “Diode Test” function of a digital meter,

which will give a voltage to turn on the diode in the circuit.

➔If any switches fail this test, replace the console panel/keypad assembly.

➔If all switches test OK, replace the machine control board.

KeyPad assembly

click on picture

Part links:

W10240046 Black

W10240047 White

W10240048 Biscuit

Source: Maytag mdb6709aws0 dishwasher inop.