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Here is the tech sheet
https://www.servicematters.com/d...0Sheet%20-%208537797.pdf

The tech sheet gives info on checking the keyboard

I would remove the ribbon cable (Keyboard to control).
Visually check the tracks in the cable, check for hairline cracks across the conductors. A magnifying glass and bending it slightly helps. Check each track for continuity with a meter.

If above OK. Clean the cable connectors and the connectors on the boards with isopropyl alcohol (available at drugstores) or electronics cleaner (available at electronics supply stores and some hardware/auto stores). Use a toothbrush but be gentle. Do not reconnect till all the solvent has evaporated. Give it a try.

If still NG run the keyboard tests etc. in the tech sheet.
If meter test show keyboard is OK probably the control board is gone but it is always still a bit of a gamble unless you can actually find a fault on the keyboard.

You will need a meter. If you do not have one I would suggest you purchase one. You can get a decent digital multimeter for under $20.00. You do not need fancy though it is nice if the leads are a couple feet long.
If it saves ordering one unnecessary part it has paid for itself.
A couple things to watch when measuring ohms and continuity
1. Always remove power from the machine otherwise you could blow your meter.
2. Always disconnect at least one side of any device you are checking. This eliminates the possibility of measuring an alternate/parallel circuit path.
3. When checking for closed contacts and continuity use the lowest scale (Usually 200 ohms). Then try higher scales. This scale is 0 to 200 ohms so if the device you are measuring is 300 ohms this scale would show an open circuit which it is not, you are just measuring outside the scale's dynamic range.

There is a good STICKY at the start of this forum about it's use.

I have the exact same dishwasher with the same problem. I have pulled out the keypad and cleaned the contacts and switches and it worked for 2 weeks. Pulled the keypad again cleaned contacts and switches and worked for 4 days. I ordered a new key pad and popped it in and nothing same symptom. I cleaned the ribbon cable contacts and checked the continuity which was good. I put it back together and no go.

As I am sitting in front of it trying to figure out the diagnostics and timing diagram I wiggled the door microswitch and it started up. This makes no sense as with the door open as you select the buttons it blinks at you once start is pushed and begins washing once the door is closed. This thing is has me baffled. I am going to replace the switch which is cheap but still don't understand what is causing the problem.

Can the main controller be intermittent like that? I pulled and flexed the boards and ribbon cable, pushed on the connections with no luck.

Any other ideas, before it started to act up the wash cycle seemed to be getting extremely long almost 90 minutes, could a flakey thermistor be the culprit?

Thanks any advice would be appreciated.

A few follow-up questions...sorry, I'm a novice. 1) The instructions say to disconnect the power before working on the machine. Is it ok to flip the breaker at the panel to shut off power to it rather than disconnecting the wiring? 2) I disconnected the ribbon cable at one end so I could examine it closely but I didn't get the other end loose because it wasn't coming off easily and I didn't want to damage anything. It's the end that attaches to the green circuit board that has the key pad/control buttons on it (the "user interface"). Can you suggest how to do that without breaking any parts? 3) I examined the user interface and see that there is rust on some of the key pad button mechanisms that are attached to the circuit board. This is probably because the plastic labels on several of the exterior control buttons on the "panel cntl" has broken so moisture has gotten in. Does that rust and the broken keypad labels mean that I should replace those parts? I don't yet understand how to go about running the diagnostics on the key pad and I'm wondering if it's worth figuring that out when it seems that moisture will continue to get into there during normal operation even if I get it working now. Thanks so much for your advice!

Thanks! Very helpful tips. This web-site is great. I purchased the dishwasher used so I'm ok with putting some more $$ into it. It seems to be in great shape and is loaded with features. I'll get it working and then decide about spending money on cosmetics (like the broken plastic on the buttons).