Help troubleshooting dishwasher

Discussion in 'General Electronics Chat' started by rjns, Feb 24, 2014.

  1. rjns

    Thread Starter New Member

    Feb 24, 2014
    I'm trying to find out why my dishwasher suddenly stopped working. Based on what I see on the front control panel, the spec sheet said it's either the control board or the control panel (keypad). I followed the fixes below per the tech spec sheet instructions, but still no go. Can someone help? BTW, I have a multi-meter, but I'm still pretty much a newbie when it comes to electronics. All testing was done with the X10 ohms setting.

    Control board:
    I got a new one and installed it, but now the LED display on the dishwasher does not come on at all. It worked with the old board. I removed the new board and checked resistance on all the resistors. I placed a probe directly on the wires on either end of the resistor itself. I tested every one and got about 0-10ohms on most, but infinity (or very close to) on a few. Does this mean I got a bad board? Since the display didn't work, I couldn't try to run the diagnostics/reset function on the dishwasher so I'm thinking it's a bad board.

    Control panel:
    The spec sheet had a table where it tells you how to test each switch for the keypad. It says to place the positive lead on a certain pin on the ribbon cable, the negative on a certain pin, then press the corresponding button on the keypad. I had infinity on every one of them. However, just for grins, I tried reversing the probes and got about 10 ohms on every one. I don't know if I'm calling them pins by mistake, but they are the contact points on the side of the ribbon cable connector, numbered from one to 14. The cable was disconnected from the board and power off. Am I doing this right? Why do I only get continuity with the probes reversed? Or am I wrong and they aren't switches at all? I had been told these keypads are button switches where the light above the key lights up when you select it. My dishwasher is a Kitchenaid Superba KUDSO1ILBL6 if that helps.

  2. Brevor

    Active Member

    Apr 9, 2011
    My experience with dishwasher repair is that the keypad fails much more often than the control board.
  3. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    My experience with "internet diagnosis" is that if you can't fix it and have to ask on the internet should just buy a new one or hire someone to come fix it for you..

    There are literally hundreds of "areas/issues" that could be causing the problem.. You aren't even sure how to work a multimeter let alone run a full diagnosis on a broken washing machine.

    You didn't even provide a detailed explanation of whats "stopped working" and just immediately bought a new control board and can't seem to replace that properly either.

    Those that can
    Those who can'
    Last edited: Feb 24, 2014
  4. rjns

    Thread Starter New Member

    Feb 24, 2014
    So do those types of buttons/keypads only show continuity in one direction and not the other? The spec sheet said if any of the buttons didn't register when tested then replace the keyboard. I just didn't understand why I got a reading only in reverse polarity.
  5. MrChips


    Oct 2, 2009
    mcgyvr is being a bit harsh on you but there is a lot of truth in what he is trying to say so please be patient and pay attention.

    1) Household appliances are not the easiest things to diagnose and repair, even for the experienced serviceman. Generally, service persons don't have the time (and knowledge) to trouble shoot appliances. They just replace complete modules and assemblies until they get it working.

    2) Notice that 99% of appliances state "No user serviceable inside". They don't want the home owner to go mucking around inside.

    3) You cannot use a mulitmeter on ohms setting to diagnose resistors the way you are going about it. In order to test a resistor you have to remove it from the circuit or at least unsolder and lift one leg away from the circuit.

    4) You cannot diagnose a circuit board by poking around with a test meter.

    5) You replaced the control board with a new one and still the dishwasher does not work.
    (a) The new control board is malfunctioning
    (b) The new control board is OK and the problem lies somewhere else.

    6) You are now stuck with a broken dishwasher and a useless control board.

    7) If I were a service person, I would be charging $150/hr to provide the information I have given you so far. Fortunately, advice given on AAC is free.
  6. MrChips


    Oct 2, 2009
    So let's take one step at a time.
    What is the model number of your dishwasher? The number you have provided comes up blank.
    What link are you referring to that provides you with assistance?

    When you say the dishwasher suddenly stopped working, can you elaborate?

    Have you been following this link?
  7. rjns

    Thread Starter New Member

    Feb 24, 2014
    Thanks, MrChips.

    The model number is:KUDS01ILBL6 (that is a zero after the S, not the letter O).

    I wasn't looking for someone to tell me exactly what's wrong with the dishwasher. I gave a brief explanation of what I was doing, but just needed help with the "am I doing it right" part. I am a novice to electronics and would just like to learn more. However, if explaining everything will help you determine if I'm performing my circuitry testing correctly, then here goes: :)

    As far as what the dishwasher was doing: "Normal" light was flashing one morning and 2 dashes appeared in display. D/W had not been used for about 3 days and was working just fine prior to that. Ran diagnostic mode, "2" appeared in display, "Normal" light now steady, pump ran for about 15 seconds, stopped, then light flashing started again. After checking appliance and some others, they all said the Normal light blinking meant the control board was bad. I bought a new one, installed it. Normal light still blinking, nothing in display. Tried to run diagnostic again, but now it wouldn't let me (which is why I thought the new board was bad). Reinstalled old board, display works, diagnostic check redone, same as before.

    This is when I pulled out the technical sheet that is found behind the toe kick panel of the D/W. It states there that a flashing light means either control board or keypad is bad. Following the tech sheet instructions to see if the keypad is the culprit, I tried to test the switch block by following the instructions for which pins on the ribbon cable to place the positive and negative probes and pressing the corresponding button on the keypad. I did this for all 13 buttons and got infinity/no reading on all of them. I thought the odds of every single switch going out at once was highly unlikely as there are a few buttons we've never used in the 9 years we've had it. I tried with the probes in the opposite polarities and got 10 on every button. My question here was, why am I only getting a reading in reverse polarity? Is that how a switch block works?

    BTW, I also tested the door switches and they are both good.

    As far as the control board I bought, since the new one won't even allow me to run diagnostic mode and the display no longer came on, I figured something must be wrong with it. The store is refunding my money. However, before I tried to replace the keypad or get another board, I was trying to see if I was performing my testing correctly. The parts aren't cheap, but I did find 2 online retailers that will allow you to "try out" the electronic parts and send them back for a full refund if it doesn't fix your problem.
  8. studiot

    AAC Fanatic!

    Nov 9, 2007
    Domestic (and other) devices generally have various internal safety cutouts / failure devices.

    One of the very first actions in servicing is to check whether any of these have operated.
  9. Gdrumm

    Distinguished Member

    Aug 29, 2008
    Your dishwasher sounds way smarter than mine.
    I tried to fix mine, and wasted some time and money.

    I wasted money by replacing the water inlet valve (solonoid).

    The problem turned out to be a rusty pipe, (under the sink) from when the house was built 40 years ago. It was clogged and wasn't letting the water flow.

    Even after I got that all fixed, it still doesn't wash worth a hoot.

    I like fixing things myself if I can, but sometimes (especially after 9 years) it's time to break down and buy a new one.

    Gook luck!
  10. wayneh


    Sep 9, 2010
    I'm pretty handy at such things I but bought a new dishwasher several years ago because I couldn't diagnose a similar problem. I was certain the larger mechanical parts (motors, valves, etc.) were working fine so it was very frustrating to toss the machine because the computer or touchpad were dead. But it would have cost far more to get those diagnosed or replaced, and then all I would have had was an aging dishwasher.

    There's a chance you got a bad board, and that another replacement will get you going again. It's a tough call to keep pursuit this when you have to keep paying shipping charges. Gets to feeling like good money after bad.

    I agree that the keypads fail (from heat and moisture exposure) far more often than the boards.