Hello internet, my name is Winter. How’ve you been? Well, lately, very elated and a tad bit disgusted. Here’s why.
You see, I live in a large family which eats in very often. That’s not much of a problem while you have a working dishwasher, but a week ago, our vintage 1980s era GE Potscrubber 1200 mysteriously stopped working and the plates piled up in the sink faster than we, due to all our busy individual schedules, could wash and stack. Yes, you read that right, it’s 2012 and my family’s 1980s era dishwasher broke down. It made pumping and whirring noises when turned on, but curiously made no attempt to fill itself with water before starting the wash/rinse cycle. So, not really an unexpected event, but really inconvenient nonetheless.
Needless to say, although we were able to function without a dishwasher, the kitchen started to look progressively worse and worse. Finally though, at the end of the week, school ended for the summer and I finally put my foot down and set about finding solutions to the eternally-full-of-dirty-plates problem.
The proposed solution? That dishwasher’s old dude, go buy a new one!
The cheaper and more immediate solution? Crack it open and try to fix whatever’s broke… Maybe…
Oh, and did I forget to mention that there will be chances to play with high voltage electricity? Yeah, that first option never had a chance. On with the hacking!
So although playing around with mains power is fun and all, I really did cut the power to the washer via the garage circuit breaker before poking around. I turned on the machine at various times to do voltage checks, but for the most time left the machine off. I did not want to be remembered as the guy who electrocuted himself fixing an old dishwasher. Can you imagine having that written on your headstone? So please, unplug your stuff! Don’t be that guy. Now enough warnings, this isn’t Mythbusters! On with the teardown!
First to be stripped off is the black bottom panel of the dishwasher. This reveals the wiring, pipes and solenoids that regulate the water flow in and out of the main wash basin. The copper tube attached on the left to the solenoid is the hot water intake line. Since everything else besides the water intake seems to be working, this solenoid probably has a lot to do with our problem. Either it’s fried and needs to be replaced, or something else that should be feeding it electricity is fried.
Let’s pop off the safety cap, unplug the supply wires, and connect our multimeter leads to the wires going to the solenoid.
Turning the dishwasher on reveals a voltage of zero across the two leads. Hmmm… So it seems like the solenoid is not our culprit after all! It must be something between the valve and the power supply. A minute of wire following leads me to my second electronic suspect: The water level sensor.
This ingeniously simple sensor uses a float and a isolated normally open (NO) switch to shut off electricity to the hot water intake valve after the water level inside of the washer reaches the required height for washing and rinsing. Could this be the problem?
A quick test using my multimeter’s continuity check function rules out the switch as the faulty component of the sensor. The circuit disconnected when I depressed the switch, and reconnected when I let go. But what about the float?
As it turns out, the water level float in this washing machine is hidden inside of a poorly vented white canister screwed into the bottom of the washing cavity. Popping off the cover revealed what I could classify as the most traumatizingly smelly and grimy piece of mechanical equipment I’ve ever encountered. Ever…. No, really. Ever.
With the float clean and reassembled, I turned the machine on again with the multimeter hooked up to the solenoid leads. Grrr! No voltage! It must be something in the wires leading up to, or in, the control board!
Removing the seven screws from the interior facing wall of the dishwasher door allowed me access to the interior of the door. After removing the protective plastic covers hiding the electronics I was finally able to see the brains that make this machine “tick.”
Hey! I recognize some of those wires! [See above left photo] Those pink and red wires are supposed to go to the hot water intake! –And they’re hanging loose! They must have snapped from the repetitive opening and closing actions of the front dishwasher door. Here they are soldered back together and wrapped in electrical tape.
Now, after already fixing multiple problems with this washer, I was skeptical as to whether this would be the last problem barring me from cleaning my well-used coffee pot. What if I go through all the trouble of rebuilding the machine and it doesn’t work? I’ll have to take it apart again! Don’t worry, just hack the failsafe with electrical tape! Apply tension via electrical tape, reset the garage electrical breaker, and voilà! The intake solenoid opens, the dishwasher fills with water, and it works again! Sweet!! Isn’t it amazing what a bit of semi-methodical poking around can get you? Now just to put it back together. Good thing I remembered where I put all the tiny screws!
This brings me to the end of one of my first blog posts. I hope you’ve liked it! I’ve finished a lot of personal projects recently and will be posting write ups of my experiences for future adventurous souls who want to get their hands dirty and void a warranty or two. Here’s my list of already finished projects that I plan to post in the next few weeks:
- Respect “root” when in the command-line! How a one character mistake annihilated my linux backup server in 10.6 seconds flat.
- Turning your computer into a packrat’s stash; How to cram three desktop harddrives into the two front CD drive bays of your computer using 3D printed parts.
- Fixing something important with Arduino, Python, Linux command-line, and regular expressions. (No, I’m not saying what yet!)
- Turbocharge your Linux server using low-level filesystem ninjutsu and /etc/rc.local run level triggers.
- Didn’t read the product page when ordering overseas from Hong Kong? Here’s a detailed, involved guide on how to cleanly hack a Verizon iPhone4S battery cover onto a AT&T iPhone 4S. Warning: Goggles and Respirator are a must for this one!