Introduction: DIY Fix Your Maytag Dishwasher on the Cheap
I used to love the Maytag brand. My old dishwasher lasted more than 20 years when I replace it with a new one a year and half ago. You can't be wrong choosing a Maytag, I thought. But I was deadly wrong.
Last week my 1.5 year old Maytag dishwasher suddenly quit working. The "Start" button won't respond, so is gone my confidence with Maytag. I searched the internet and found many unhappy customers complaining the same: the touch buttons failed shortly after the warranty expired. There are basically two options, one is to get the repairman here to fix it. The chances are that he will just replace the control panel, as well as the control board with about $150 each. Labor is probably another $150, which would easily totals to $450, about the same amount as a new dishwasher. The other option is to simply buy a new one, and trash the old-new one - what a waste! The premature failed dishwasher would be in the landfill, and polluting the environment, or used as scrap metal, wasting energy. Either way you are a loser, while the salesman will be laughing all his way to the bank.
I searched the web for DIY solutions, and learned to get the diagnostic manual from the bottom panel, and then found the root cause for the failure, and finally fixed it with very little cost. Now my dishwasher is working again. Here is how I did it step by step. Hope you can benefit from the instructions here.
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Step 1: Find Out What's Wrong With It.
It's easier said than done but with the diagnostic manual, it can be done. I run two diagnostic tests which allowed me to conclude that the problem is not as serious as I initially thought. First is to put the dishwasher in diagnostic mode. In my case it is to push the "normal->heated dry->normal->heated dry" in sequence rapidly. The washer then resets itself and runs for a while although it never finishes. It didn't solve the problem but it gave me a feel that it wasn't totally dead.
Then another test is to separate the fault of the control panel from that of the control board. This requires the control panel to be removed from the door following the instructions in the manual. Make sure the power is turned off at the fuse box so you don't get an electric shock. Then disconnect the cable from the control panel to the control board (a gray box about the size of 6x10 inches). Then turn the power back on. Once the door is closed, the dishwasher will start to drain with the motor running. This would be an indication that the control board is functioning property. I had doubts about this since the control board could still be bad even it passed this test, but that wasn't the case. Well, I guess the control board is better built than the control panel. In my case, the motor run which suggests the fault is at the control panel.
The control panel is simply a piece of plastic with all the touch keys and a cable. What can be wrong? I carefully examined the control panel and didn't find any problem initially. Then on the back of the cable, I found a small spot on some of the 14 wires on the Flat Plastic Cable (FPC). It looked like part of the cable but actually it was rust! After removing the rust, it reveals that the wire was broken at that spot for several wires, which explains why the "Start" button won't work.
I further tested the connectivity using a multimeter following the instructions in the diagnostic manual. Sure enough the wires were open for several buttons, so the root cause of the problem was found.
Step 2: Fixing the FTC Cable Is Both Hard and Easy.
The FTC cable is part of the touch key panel so there is no way to just replace the cable. What's worse is that the cable is paper-thin and you can see through it. I initially tried to use solder iron and ended up with some holes. So the old fashioned way of fixing broken wires doesn't work with the printed circuit on the FTC cable.
After some research on the web, I found the wire glue which might work, but then had mixed review from users. At the same time I found the "Rear window defrogger repair kit" by Permatex and I though that it would work. I bought a kit from the local auto part store (advanceauto) and found a tiny bottle inside this big box. It wasn't clear whether this would actually work on a flexible plastic cable.
I carefully scrapped off the rust at the broken wire on the FTC and exposed the copper layer which is paper-thin. Then used a toothpick to apply the repair paste to make the wire connection. Let it dry for a day and then measured the resistance. It is about a ohm which is not too bad (not totally conductive). After making all the connections for the broken wires, I followed the diagnostic manual to test the connectivity for the 14 pins using a digital multimeter in diode mode. For example, in my case, the "Start" button uses pin 12 for positive and pin 4 for negative. It shows about 670 ohms when the start button is pressed for connectivity because it has an internal diode. Using this procedure, I tested all buttons.
It's a good idea to also test for short circuit. I actually had one in my first try because I had to use copper wire to make up for the burnt hole. The thin copper wires actually caused a short between two pins. As a result, I had to take it apart again to fix it. It's better to test for short between adjacent pins before it is put back together.
Now the question is how to insulate it. I thought about the liquid tape but that appears to be toxic which is not acceptable for dishwasher applications. Then I found the Super 33 tape which appears to be good for this application. I got a roll from Homedepot for about $5 and taped all the connections before putting the control panel back to the dishwasher door.
Finally, the magic moment came. I push the start button and the dishwasher is back to life.