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SERVICEMAN’S LOG The dishwasher that wouldn’t Dave Thompson It’s that time of year again when everyone seems to go a little mad. I know I do! Unfortunately, our dishwasher decided to go a little mad as well, leading to me calling in the big guns. It has been playing up for a while and we’ve been doing the usual things, running commercial cleaners through it and putting in bowls of vinegar, the sort of fixes suggested by the internet. The filters are always a good place to start; this stainless-steel German-branded model we have now has quite a good system for ease of access and cleaning the filters. They were all clean, but I could hear a faint grumbling sometimes while the machine was doing its thing. Suggestions were made that something had gotten through to the pump and it was causing problems, but I just couldn’t see how that was possible given the filter system. It is, of course, possible we lost an impellor blade or something else had come loose beyond the filters and was fouling the pump. Still, I couldn’t see anything in it, and surely it would be making a much more noticeable noise if that were the case. We put up with still having dirty dishes in the morning on the odd wash cycle, but it got progressively worse over time. This unit is around five years old, and it isn’t the original dishwasher we put in when we renovated this house. That was a Samsung model, using a different type of technology to the rest of the pack (I’m a sucker for trying 94 Silicon Chip new things!), yet it really never worked properly. It would fault often, and I wrote about it at the time, because at under two years old, it should have performed way better than it did. I sold that appliance cheaply to a local repair guy who said he knew what was likely wrong with it and waved goodbye as he drove away with it on his trailer. Of course, we took quite a financial hit, but we simply wanted a machine that worked and cleaned the dishes without faulting or stopping half-way through a cycle. This new fancy German one was far better in every respect, from the clever folding dish-retaining system to the almost silent operation. Stealthy silverware scouring The latter isn’t a huge selling point for me, as we put it on downstairs overnight, but it is amazing how quiet it is. The only noise from it usually is the odd water-draining gurgle – which is, of course, not the dishwasher per se, but our drainage system, and the beeping when it finishes a cycle. We’ve been very happy with it, and it does a fantastic job of washing dishes. Until recently. As I mentioned, I’d heard the odd grumble from it, which was all the more obvious as it is usually so quiet. It didn’t seem to make much difference to the operation, though, and there were no error codes thrown up or any other sign that something was amiss. The dishes still washed OK, and everything seemed tickety-boo. But then it wasn’t. We started noticing that the cutlery, which sits in a sliding tray at the top of the machine, was often not washed properly. There is no dedicated rotating arm for this tray; instead, the one under the middle glasses tray must spray this cutlery tray as well, and it just wasn’t doing it. We would often also find the pellet undissolved sitting in the middle tray. It is designed to pop out of the dispenser and sit in a soap-dish-type tray that doubles as the handle for pulling the basket out of the machine. Those rotating arms come off relatively easily, so I disassembled them and washed them in the sink with detergent, ensuring all the water holes were clear, and they were. They seemed very clean and unimpeded, so if it isn’t them, it must be the pump not delivering the water properly. I checked the input water line to make sure it was clear and flowing properly, which it was. And that’s about the extent of what I could do. I visited the product’s web page and downloaded the usual manuals and documentation. The suggestions for this sort of concern were mostly what I’d already done. Australia's electronics magazine siliconchip.com.au Items Covered This Month • Dishwasher repair • Closing the case on a roller shutter • Repairing an off-grid water heater • A faulty leaf blower charger Dave Thompson runs PC Anytime in Christchurch, NZ. Website: www.pcanytime.co.nz Email: dave<at>pcanytime.co.nz Cartoonist – Louis Decrevel Website: loueee.com I wasn’t about to drag it out and take the sides off – that is beyond my pay grade. I’ve done it before on an older model dishwasher, but this one is much more intimidating. There was nothing for it but to book one of their techs to come out and have a look, something we could do easily through the web page. This is a great feature as it would be a serviceman very familiar with the brand. I gave a detailed description of the problem in the web form and all our other details and hit the ‘send message’ button. Time to call in the experts Within a day, a guy called, and we made an appointment for him to visit just a few days later. I initially thought I might have to wait for several weeks, so this was a pleasant surprise. He said he knew what the problem likely was and would bring some parts. Excellent service so far! As is usual for this type of serviceman, he could only give us an approximate time between 1pm and 5pm. This is fine for us because we work from home, but it would be pretty annoying if I had to take half a day off work just to wait around for him. I guess that’s just the way it works; many of the jobs they do, they don’t really know how long it will take. This reminds me of that Soviet man who decided he wanted to buy a Lada. He was told that the waiting list for the car was long and he would get it exactly three years from today. He asks, “will it be ready in the morning or the afternoon?” The salesman is shocked and responds, “It’s in three years. What difference will it make?” He responds, “well, the plumber is coming that morning”. Anyway, to be fair, I get asked this all the time when someone drops a machine in to me to troubleshoot: how long will it take? I always ask them, how long is a piece of string? Unless I know exactly what the problem is (often I do), I can’t give an accurate time-frame until I get well into it. If I don’t know what I’m dealing with, I don’t know how long it will take. All I can do is call the customer and tell them once I find the problem, which I usually do anyway, especially if it is going to cost more. I’ve always operated with a ‘no surprises’ policy. I don’t just spend hundreds, then present them with a bill, giving them the option of what to do and which way to go. That is, unless I can fix it quickly and inexpensively, in which case I call them and tell them it is ready. I suppose people are worried about mounting costs if it is going to take a while. As it turned out, he arrived at around 1:30pm after calling siliconchip.com.au ahead 30 minutes before to let us know he’d be there then. Again, good service. Operating on the patient When he arrived, he put down some protective blankets on the floor and tried a few cycles on the washer, which he could cancel at any time, and he confirmed the pump was the likely culprit. Of course, he did what I’d done, checking the inflow and outflow and filters. He then pulled the washer out from under the bench and onto the groundsheet, and whipped the covers off with well-practised ease. It was obvious he knew exactly what he was doing, and all the while, he kept up informational patter as he went through it. Just looking at the insides, I was glad I didn’t try this. It looked hugely complex compared to the one I pulled apart years ago, with tubes and wires and valves everywhere. It was also stuffed with sound-deadening material, with wires and tubes buried in it, so I really wouldn’t be comfortable tackling a job like that. I guess now we know why it’s so quiet! He sat on the floor on the side away from where I was standing so I couldn’t really see what he was doing, but he passed me the pump assembly he’d just removed like a surgeon handing a nurse a freshly removed organ. The manufacturing quality of this component was unlike anything I’ve seen in a long time. It looked like a turbocharger from a car and boasted a hard plastic body and water connections, but the quality of the plastic and the moulding was amazing, and I marvelled at the compactness of it. The guy said it was quite rare for a pump on this particular model to fail after such a relatively short time, so the company would be replacing all the parts he used on this repair under warranty, even though technically it was out Australia's electronics magazine March 2025  95 access some such fasteners, so I completely understood this guy making his own custom tools. Anyway, he finally finished installing the bits and bobs he’d brought with him and plugged the washer back into the power socket. Everything else was still connected, so he ran a quick cycle through it and seemed satisfied it was all working properly. It certainly was much quieter, even with the sides off; we must have gotten gradually used to the noisy pump. He soon had the sides back on and, after a quick clean over with a rag, had it all looking perfect. He slid it back into the gap under the sink, ensuring all the hoses and cables were in the right place and not crimped or kinked. We had some dishes in the sink, so I loaded it up and put a pellet in it and set it to do a 60-minute cycle, the usual setting we use it on. It worked perfectly and I couldn’t hear it at all now! I guess when something starts grumbling we don’t hear it after a while and until the problem is resolved, we just consider it ‘normal’. But of course, it isn’t normal. It’s like a loudly ticking clock – after a while, we don’t hear it because our brains just negate the sensory input. Manufacturer support is worth paying for the other side of our warranty period. We would only be liable for this guy’s fee. He also replaced a couple of sensors and valves while he had it apart. The pump assembly retails for about $500, so I’m glad they were covering it! I’m not sure what the sensors and valves would cost, but he said it would be a good idea to replace them while he had it apart, and they were paying anyway! Another big tick in the good service box. It seemed like a relatively tricky job putting it all back together, if the time taken was anything to go by. As I wrote, I couldn’t see what he was doing, but he was elbow-deep in the guts of this machine for quite a while. Our galley-style kitchen is quite narrow and, with the machine in the middle of the floor, there was no getting past it. I could have gone around and come up from the other way, but I really don’t like people hovering over me while I work, so I extend the same courtesy to other servicemen. I was interested in his tools, though, and had a discussion with him about that while he worked. He was quite happy to chat. He had what looked like a pretty comprehensive toolkit, and I could see a few special tools he’d accumulated over the years, likely for all the different models he’d encountered. While some were supplied by the various manufacturers, others he’d made himself from existing tools. Dad and I did this for various cars I’ve owned and ended up doing my own repairs on. British cars especially had some bolts and nuts in crazy places, as if they suddenly thought, where is this Fitzer valve going to fit? I know, we’ll put it behind and under the engine next to the firewall and make the nuts and bolts impossible to get to! We fabricated many special spanners and wrenches to 96 Silicon Chip We are lucky in that we bought a known, branded appliance, and we did so because the last one had let us down so thoroughly. The old adage that you get what you pay for is especially true these days. That said, some of the cheaper appliances work just as well, but it is always a risk to buy them given they often have no official after-sales technical support. Instead, you have to rely on some random service guy who might be able to fix it when it breaks. Or perhaps not. I imagine some of the parts for those cheap, big-box store models would be nigh on impossible to get, unless of course they use the same parts as some other brand, like some TVs sold here under other names. Many use the same PCBs as big-name overseas brands, but finding out which parts are compatible can take a lot of time and research. I’ve found online forums very handy for this, as many service people post in them and I’ve had many questions answered by the people who frequent those forums. They tend to share their knowledge freely. At the end of the day, buying the best we can afford is usually a good practice, and this appliance illustrates that, with the company standing behind their gear and supplying parts for them because they know they will wear out one day. The pump went pretty early, I suppose, but we run it every night and it has done a lot of work in the time we’ve had it. Servicing Stories Wanted Do you have any good servicing stories that you would like to share in The Serviceman column in SILICON CHIP? If so, why not send those stories in to us? It doesn’t matter what the story is about as long as it’s in some way related to the electronics or electrical industries, to computers or even to cars and similar. We pay for all contributions published but please note that your material must be original. Send your contribution by email to: editor<at>siliconchip.com.au Please be sure to include your full name and address details. Australia's electronics magazine siliconchip.com.au Nothing lasts forever, and with built-in obsolescence increasing, it is only going to get worse for consumers. That’s even before you factor in totally unexpected events like the pandemic, which shut factories down all over the world and created a huge parts vacuum that has still not been filled. It is increasingly difficult for me to get computer parts, for example, with my traditional suppliers only stocking a fraction of what I could get from them pre-pandemic. This has a knock-on effect on customers who might be looking for a new machine. While it appears that some stores seem to have an abundance of parts, they could have either bought a container-­ load before the pandemic, or have some pretty good contacts in Taiwan and China where they can snap them up before any of the more traditional suppliers can get their hands on them. Either way, it makes my business difficult. Thank goodness for the guy who fixed our dishwasher, though. He was prompt, professional and claimed that all parts were available for it. For a 5-year-old appliance, that’s not bad these days. It has been going flawlessly since he swapped the pump out, so that was obviously the problem. He took the old one away, but I wished I’d taken a photo; it really is a beautifully made item – classic German engineering! I guess it could be a different story if something goes wrong with the electronics or the touch-activated control panel, but I guess we’ll cross that bridge if we come to it. dropped on the bench top with a noticeable ‘clunk’ noise. Looking at the top of the PCB, the remote had obviously been dropped from a fair height, producing enough force to separate the inductor body from its mounting pins. This is another example of poor design, with the inductor’s ferrite body being much too heavy for the support provided around its mounting pins, which just disintegrated when it was dropped. Could I fix the inductor, would I need to rewind it, or bite the bullet and source a replacement? Luckily, it was at least labelled, so at least I knew its value was 470µH. After a careful (magnified) look, I saw that, luckily, there were two enamelled copper wire pigtails sticking slightly out of the bottom of the inductor. So it looked like repairing it was at least theoretically possible. The repair turned out to be relatively easy. I tinned both pigtail ends, then carefully positioned the longest pigtail over its PCB pin and soldered it in place. To minimise the chance of future separation, I used superglue to hold the inductor body in place. I considered using silicone sealant, but it takes a several hours to provide sufficient mechanical support, whereas superglue (aided by Zip Kicker for instantaneous hardening) dries immediately, with high mechanical strength. I then soldered the other pigtail in place and added enough superglue to provide a really strong mount. Thinking about what else I could do to stop the inductor separating from the PCB again, I temporarily reassembled the case and realised there was no mechanical support on top of this heavy inductor, so I also glued some high density sponge rubber to the case, which provides the necessary extra mechanical support. Apart from the unfortunate synergy of poor inductor design combined with the lack of any support above the inductor, this remote appears well made. However, these two design flaws would have been sufficient to have consigned this expensive remote control to being ewaste; just another example of an expensive item ($140) ruined by the manufacturer saving 50¢. I was also surprised at the large capacity of the batteries in this remote control. They are much larger than usual, with a four-cell pack of 14500 AA-size lithium-ion rechargeable cells. That’s quite a massive increase over the single tiny Repairing a roller shutter remote control My daughter runs a local primary school canteen. Yesterday, she dropped a largish remote control in my hot little hand and said that the battery won’t charge and it doesn’t work. I decided, as I usually do, to remove the four Pozi­ driv self-tappers and have a look inside. Fault diagnosis turned out to be super easy because, as I prised the two plastic covers apart, a small ferrite inductor siliconchip.com.au The opened-up remote control for the school canteen roller shutter door. Australia's electronics magazine March 2025  97 coin cell used in car and garage door RF remote controls, or the two AAA cells in IR remotes. Happily, my daughter reported the next day that, after charging the battery, everything was working again, with no problems feeding her ravenous horde of school kids. G. C., Cameron Park, NSW. Joolca HOTTAP V2 repair My daughter rang and asked if I would help her partner fix their portable off-grid water heater, which had stopped working. It connects to a water source and an LPG gas bottle. There was a digital temperature gauge and controls to set the water and gas flow to adjust the temperature of the hot water outlet. It is powered by two D cells in a battery box. We decided to check the batteries and battery box to make sure the heater had power. The battery box simply unscrews from the unit, providing access to two terminals that feed the heater. I measured the voltage at 3.2V, which is fine. Next, we took off the cover to check for any obvious damage. The heater has an ignition coil, a solenoid to control the gas flow, a Klixon thermal switch connected to the outlet pipe, a microswitch that looked like it operated when water flowed through the system and various other components. Nothing seemed to be damaged or loose. We decided to connect the heater to the garden tap and see if anything happened. The display did not show any indication, and nothing else seemed to be working. Overnight, I visited the Joolca website and found that the most common fault was flat batteries. I also discovered that if the Joolca logo on the temperature gauge was pressed, a fault indication should be displayed. The next morning, I had another look at the battery box. I pressed the Joolca logo and there was no indication on the display, so maybe no power was reaching it. I then removed the battery holder and measured the voltage as I had on the previous evening; I got a reading of 1.6V. Obviously, something was wrong with the power. I checked both batteries, which were about 1.5V each. The batteries are connected in series by a metal strip in the battery box lid. When I examined the holder under my magnifying light, the spring on which the negative of one cell sat seemed to be loose. I found that if I wriggled the battery, I could get a voltage reading. So it looked like the fault was a high resistance in the battery caused by the loose spring. I had to cut two plastic tabs to remove the metal strip from the plastic lid, then clean and re-attach the spring. When I put it all back together, with the metal strip glued in place, I measured 3.2V at the terminals and get the display to show a fault code, indicating no flame. So my initial measurement of the voltage the night before was obviously a fluke, with momentary good spring contact. I reinstalled the cover and connected the system to the garden tap and my LPG bottle. When I allowed water to flow, I heard the ignition sparking and the gas solenoid operating. The temperature gauge showed water temperature The top three photos show the Joolca HOTTAP V2 unit and its faulty battery connector. ► The bottom-most photo shows the charger used in the leaf blower, which had the wires shorting each other due to damaged insulation. 98 Silicon Chip Australia's electronics magazine siliconchip.com.au increasing, so the heater was working. My daughter was happy to have hot water when next they go camping. J. W., Hillarys, WA. Leaf blower charger repair I bought a Black Eagle leaf blower many years ago on eBay. Over time, I have repacked both batteries with new 18650 cells, as documented in the Serviceman column of the June 2024 issue (p92; siliconchip.com.au/Article/16294). I also repaired the charger after the wire broke at the plug end. I later had to re-solder a wire on the leaf blower’s power switch, as one of the wires had come off. The leaf blower is still working well but this morning, my wife told me that the original charger was not working and the LED was not lighting. First, I plugged it in to a different outlet to verify that it didn’t work, which was confirmed by the fact that the LED did not light up. On closer inspection, I found that the insulation on the wires next to the cable strain relief was broken and the bare wires were touching each other. I wondered if the charger would still work after the output had been short-circuited. I removed the charging cable, separated the remaining bits of wire and plugged it in again. The LED lit up green, indicating that it probably still worked. The next problem was to separate the two case halves; they were glued together, rather than being screwed. This is very annoying and makes repair difficult. I took the charger out to my workshop and got a wood chisel and hammer. I carefully went along the seam with light blows, working my way around the entire charger. This worked without breaking the charger case, and the two halves separated. Next, I pulled the remaining cable out of the cable strain relief and fortunately, it came out without too much trouble. I turned my attention to the circuit board, which had something that looked like contact adhesive over the wires where they entered it. Scraping this off with the point of a knife was successful, so I could desolder the wires from the board. I shortened the cable and tried to get it back through the strain relief, but this proved to be quite difficult. In the end, I bared around 30mm of the cable end and tinned it. I was still having problems getting the cable through, but found that I could do it by separating the wires and feeding them through one at a time. I have used superglue to secure the cable to the strain relief in the past, but I decided not to use it for this repair in case I needed to fix it again later. So I tied a knot in the cable to prevent it from pulling out. This might not be ideal, but I have found quite a few devices with this done from new, so I did the same. The circuit board had terminals labelled B+ and B−, which made it easy to know which was positive and which was negative. I knew that the plug was wired centre positive, but I double-checked the output of the new charger just to verify this. Then I used my multimeter on the ohms range to verify that both wires of the cable were intact and to identify which was which. I soldered the wires to the PCB and tested the charger before gluing the case back together with superglue and clamping it in the vise until the glue dried. Another successful repair and another item saved from the scrap pile. B. P., Dundathu, Qld. SC siliconchip.com.au Australia's electronics magazine March 2025  99