I like our modern front-load washer for many reasons. For one thing, the gentle action and large capacity means our camping gear, from tents to sleeping bags, will not get a lot of extra wear and tear in the laundry. I also like the warp-speed spin action, as it means things we dry in the dryer take less energy, and the things we dry on the clothes line dry quickly. All this comes with a cost in that an electronics module is required for motor speed control in lieu of the old-school mechanical timer.
I had a nagging problem with bad connections that I thought was due to fretting on the connectors (fretting is an oxide buildup due to vibration of a connection). The Internet was more than helpful in identifying the fretting issue specific to this washer, and I spent a good deal of time plugging and unplugging card edge connectors every few days to resolve the problem.
It was not until I took the top off and I had the door relay kick on that I noticed a curious flash near the circuit board. I then discovered a telltale spray of oxide and soot on the inside of the plastic housing underneath the circuit board where the relay resides. It was clear once I removed the circuit board that poor solder joints for the relay had finally gone from intermittent to hard failure. The connector tabs were outlined with a dark fracture in the solder joint.
I suspect the poor solder joints stem from early attempts at RoHS compliance. With a little work with a soldering iron, I repaired the connections for good, or at least the last two years. I can accept that, in lieu of the twice-a-week disassembly and jiggling connectors, with mixed success. While I was there, I retinned the card edge connectors to address fretting issues, just in case.
The lesson learned in this case is that there is still an amazing amount of electronics problems that can be identified by careful visual examination, with no test equipment required.
I still love front-load washers for their economy and performance, and now I have one that performs as it should.
This entry was submitted by Ken Lillemo and edited by Rob Spiegel.
Ken Lillemo has worked for the last 26 years as a process engineer in a low-pressure lab.
Tell us your experience in solving a knotty engineering problem. Send stories to Rob Spiegel for Sherlock Ohms.
Ken, I could totally use your attention to detail right now. I have a front loader that is experiencing difficulty powering up after having to break the latch to get the clothing out (don't ask). Parts have been replaced and the repair man has been out multiple times with half-baked suggestions and solutions. No one is looking closely at connections or doing any kind of hard-core engineering troubleshooting or soldering work. I wish repair men were trained more along the lines of your approach. If they were, perhaps we could move beyond our "throw-away" society that has people like me already contemplating the pain of having to replace what is a relatively new washer.
Beth, the relay with the bad solder joints I repaired controlled the front door latch. I think the symptoms you describe are very close to the symptoms we experienced.
I don't need to ask about breaking the front door latch, I was nearly driven to that circumstance myself.
One good thing about this washer design is the system controller is easy to get at. Since the controls are on the front panel the top has no electrical components attached. Just a few screws are required to remove the top and the system controller is right there.
We had the same problem with the front loading door latch many years ago when we wanted to add softener to the final rinse. We could stop the washer with the timer b y pulling out on the knob, but the door remained locked. The simple fix was to unplug the unit. The door then opened easily. I rewired the power outlet by replacing the two-outlet box with a four-outlet box, in which I installed two outlets and a switch for the washer outlet. (The gas dryer plugged into the other outlet.) When it was time for the softener addition, we pulled the timer switch, threw the wall switch, opened the door, added the cap of softener and retuirned the washer to normal operation with the door shut and power on.
The new (last year) washer has a softener dispenser. I finally lost the battle to my wife, who complains, "When you are married to a man who fixes things, you never get anything new".
I had a similar problem with the ice dispenser in my high-end fridge. It would run intermittently, at best. After removing the assembly and examining how the drive motor was soldered to the control board it appeared that they only bothered to solder two of the four tabs to the board, probably just to provide mechanical support. The other two leads were unsoldered and were a poor press-fit. Adding another few grams of solder corrected the problem.
I also bought a wind-up LED flashlight that had three LEDs. After a few weeks only one LED remained operational. In this case all three LEDs were simply press-fit into the board - square pins in round holes. Six drops of solder and it's still working years later.
How much of this stuff ends up in landfills due to poor engineering decisions and/or manufacturing processes?
"Ken Lillemo has worked... in a low-pressure lab." I wish more employers would provide their employees with a "low-pressure" work environment!
Nice comment on our "low pressure" work environment. Yes, I could have said "Vacuum Lab" as that is how the sign outside the door reads. But, this being a high brow engineering publication, the invetable discussion would start about there being no such thing as a vacuum.
We do have a whole series of jokes around the office poking fun at our work. Most are along the lines of:
"This job sucks" and "If at the end of the day I have absolutely nothing to show for my work, I have done a good job."
We are on an ocean literality just a few hundred yards away and we are also if that is not hostel enough we deal with rocket launches that exhaust spent solid rocket fuel that is highly corrosive. We have hundreds of connectors at theses launch pads for photo systems that are essential for engineering data. What is a technician to do to keep these system going? Well we have constant quality control meetings on improving our systems that very much have to do with electrical and data signal connections. We have worked with connection manufactures and suppliers for recommendation and field trails of many types and technologies of connections. Chemicals to protect connection pins. Cleaners and sealers for maintenance of connections. We even are trying transportation sealed connectors used under vehicle hoods that are out in the elements and deal with extreme heat, cold and of course liquid and chemical infusion. So we are always visibly looking at our connections as a practice and we take it very seriously that every system element works all the time. We understand that physical inspections can not be substituted.
IF you want to "blame" someone for this short-sighted engineering, blame MOTOROLA! For those of you old enough to remember, MOTOROLA made a big advertising campaign out of their newly designed & configured TV sets & other home entertainment products with the "WORKS in a DRAWER" concept in the late 1950s & 1960s. They incorporated all of the low level circuits onto printed circuit boards. That was a distinct departure from the hand-wired sets of the era.
They advertised that IF a module went bad, the serviceman could come and easily replace the entire module, and you'd be back in businees in no time flat. It was meant as a counter to the common policy that service people would remove your TV or other component to repair it at the "shop". It was cast as a money-saving idea. From there, the floodgates literally opened, since many other companies adopted similar design guidelines, so that EVERYTHING one buys today has become a modular "throw away".
Your tale reminds me what else I did. After I re-tinned the card edge connectors I cleaned them with a contact cleaner that, besides removing oxide, leaves a little mineral oil on the surface to reduce contact oxidation.
Ken, I'd like to know more about what you mean by the poor solder joints being due to early attempts at RoHS compliance. I can guess--some years ago I wrote in some detail about the problems associated with solder replacements to meet RoHS requirements. Can you elaborate a bit?
Sure Ann, I should state first off, I am only talking about an impression. I have not looked at the date of manufacture to accurately place the timeline with general RoHS compliance or to look for any detailed marking on the PWB. I think the module is at least 5 or 6 years old.
I confess I have more 37/63 Pb/Sn solder in various gauges than I will be able to consume in my lifetime. The only nod to lead replacement I have made in my personal life is to replace all the water pipes in our home and use Sb/Sn. Having a ready supply of "the Good Stuff" I repaired the fractured solder joints and retinned all the card edge connections with Pb/Sn.
I am afraid I only have anecdotal evidence and suspicions to cast aspersions on early RoHS compliance failures.. However, overall the solder job on this board I would rank as terrible, even by my amateur standards.
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