Fullscreen HTML5Med Res (??MB)HTML4

SERVICEMAN’S LOG The Wimmera Boys I was in our factory in Melbourne when Raelene, our Admin Manager, popped her head into the production area and said that a young man was on the phone looking for a job after completing his electronics degree at RMIT in Melbourne. As a hands-on technician without a degree, I rolled my eyes and imagined that the hopeful young man had never seen a soldering iron. Still, I asked Raelene if he mentioned any skills he could bring to our company. She shook her head, but then went on to say he hailed from a farm near Horsham in Victoria. That lightning bolt hit me hard; it meant he had to be a Wimmera farm boy. My reply to Raelene was instantaneous: tell him he has got a job and starts on Monday at 8am sharp! Why are Wimmera boys renowned around the world? We need only remember that they were in the trenches on the Somme, the Kokoda Track and in the mines and drilling rigs in the Pilbara in the 1970s. True to his roots, young Richard turned out to be a stellar engineer. He did circuit design, microprocessor design and heavy code all destined to be exported worldwide in our drink can measurement systems. That is how Richard and I ended up heading north out of Kansas City on Interstate 29, bent on making St Joseph, Missouri before dark. We were due at a large can-making plant to service and update the software on our automatic measurement gauge. The next day, we fronted up at the plant and obediently obeyed the sign asking us to leave our guns in the car before signing in and taking our toolboxes to the plant’s laboratory. The QA Manager said the gauge was running well and left us to it. Richard set about connecting his laptop to start updating the software while I unscrewed panels to inspect the gauge mechanism and calibrate the internal probes and sensors. Things were going well until someone, also a Wimmera Boy, let the screwdriver brush against the MP44 microprocessor board, causing lots of sparks! The gauge jolted, air cylinders stopped mid stroke and the screen instantly displayed the classic black screen of doom! Richard looked stunned and immediately rebooted the gauge – nothing happened. He shook his head and confirmed that I had ‘taken out’ the microprocessor board and that we didn’t have a spare. Items Covered This Month • The Wimmera farm boys • An Acer laptop and a missing battery • Repairing a Simpson washing machine • Installing an irrigation controller • Plus a faulty alarm controller Cartoonist – Louis Decrevel 84 Silicon Chip Website: loueee.com We felt sick – the gauge was running well until we blew it up – our American customer was not going to be happy! What to do? I sat and went through our options; they were all bad. Richard walked around the laboratory and suddenly yelled, “Hey, look up on the shelf at the box with a kangaroo on the side!” He pulled it down, and we saw the words Versatile Technology, Made in Australia on the box. Rummaging through the contents, Richard pulled out a brand-new MP44 microprocessor board. Richard swapped the MP44 boards, and the gauge came up. Now forbidden from approaching the gauge, I watched him calibrate and upgrade the gauge software. The customer was delighted to see a new calibration sticker on his gauge. We told him about the board and that we would be sending a replacement board free of charge. So, what did we learn that day? Firstly, don’t drop a screwdriver on a live board! Secondly, encourage customers to purchase a box of recommended spare parts with their gauges, and thirdly, and most importantly – when all around is doom and gloom, hope that a Wimmera Boy walks into the room! Gerard Dean, Versatile Technology, Oakleigh South, Vic. Acer Aspire 5735Z laptop repair My son came home from town and gave me an Acer Aspire 5735Z laptop that he’d picked up at the Tip Shop. It didn’t have a battery and the lid was jammed shut. Still, I got the lid open by pushing on the broken latch release with a metal rod. With it open, I could see that it was in reasonable condition for a Windows Vista laptop that was 18 years old. Australia's electronics magazine siliconchip.com.au This Acer Aspire 5735Z laptop was purchased without an internal battery, and the lid was jammed shut. I connected a charger and pressed the power button to start it up. Of course, the CMOS battery (cell) was flat. After setting the time and date and rebooting, Windows 7 Enterprise loaded, with a message that Windows was not genuine. I’d be wiping the hard drive anyway, but I clicked on “Ask me later” so I could open Notepad to test the keyboard, which was good, with all the keys working. I also ran msinfo32, which showed that it had an Intel dual-core T3400 CPU at 2.16GHz and 2GB of PC2 RAM. I shut the laptop down, got out my salvaged PC2 RAM and found a matched pair of 2GB modules, then installed them. Now the laptop would not boot. I checked each module and found that one was bad, so I got another matched pair and this time the laptop booted. I turned it over and removed the large back cover, which revealed the hard drive, RAM, Wi-Fi card and CPU heatsink. It would be very easy to upgrade the CPU on this laptop, but I still needed to replace the CMOS CR2032 cell, which was on top of the motherboard. I removed the keyboard, hoping that the cell might be under it, but it wasn’t, so I removed the screws on the bottom of the laptop and started prising the top shell up from the front. I could see the CR2032 cell in a holder not too far in, so I was able to use a tool to flip it out and replace it without having to completely dismantle the laptop. I pressed the top shell back down, turned the laptop over and reinstalled the screws holding the top and bottom shells together. I removed the CPU/GPU heatsink by undoing three screws. I looked online to find what CPUs were supported by this motherboard; the choices were limited, as it has a GL40 chipset, which limits the front-side bus (FSB) to 800MHz. This ruled out using an Intel Core2Duo P8600 CPU at 2.4GHz (1066MHz FSB), but I had an Intel DualCore T4500 CPU at 2.3GHz that I could use. The motherboard supports the Core2Duo T8300 CPU at 2.4GHz but I didn’t have one. Still, I can obtain one for less than $10 from China if I wish to upgrade the CPU later. After researching the performance difference, I decided to order a T8300 from China to upgrade the CPU later. With the T4500 CPU fitted, I cleaned the heatsink, applied new heatsink compound and refitted the heatsink/fan unit. I noticed that the heatsink was completely clean and the fan only had a very slight trace of dust on it, so it may have siliconchip.com.au been cleaned at some time in the past. There was evidence of this large back cover having been removed previously (two of the screws were missing). While working on the laptop, I’d freed up the lid catch, so it now worked. However, the front of the catch was broken off, so it needed to be fixed to make it usable. I looked through some scrap laptop shells and found a serrated piece on one, so I broke it off and filed it to fit in the recess on the lid catch. I carefully glued it in place with superglue, which is ideal for gluing ABS plastic, as it partly melts the plastic, ensuring a good bond. I looked through my salvaged batteries to see if I had a battery to fit this laptop, but I didn’t. I’ve previously wrecked several non-working Acer laptops, but they were completely different models, either with no battery supplied or a completely different type. I looked on eBay for a battery, but they are between $40 and $50, so I won’t be buying one. I’ll just use the laptop with the charger for now. Maybe a battery will turn up later. Australia's electronics magazine November 2026  85 I refitted the keyboard, then booted the Memtest86+ CD to test the newly installed RAM, which passed. Now I could think about installing Linux on the 160GB hard drive that came in the laptop. Whenever I get a second-­ hand laptop, I always erase the hard drive contents. The previous owner probably should have done that but they often don’t. I installed Big Linux, but after restarting, the laptop would not boot. I wanted to have a look at the new Zorin 18.1 distro, so I tried to install it to dual boot, but the installation crashed partway through. I suspected there was something wrong with the hard drive, so I swapped it out for a 320GB drive, but upon reinstalling Big Linux, I saw CD read errors. I knew the disc was fine as I had used it successfully before, so it was the optical drive that was at fault. I swapped in a spare one after changing the faceplate and the bracket on the back, and this time I was able to reinstall Linux. It can be interesting to try different Linux distros and see what they are like. Some of them install more smoothly than others on these old systems. For anyone considering switching from Windows or macOS, it’s better to stick with reliable mainstream distros. While Ubuntu is quite popular, I’ve found it to be somewhat of a learning curve for anyone switching from Windows. Kubuntu or Lubuntu are good for old hardware (especially Lubuntu). Linux Mint Cinnamon, which I’ve installed on my wife’s laptop, is a lot faster than Windows 10. Bruce Pierson, Dundathu, Qld. Simpson 9.5kg washing machine repair My wife told me that she was having trouble opening the lid on our Simpson 9.5kg washing machine. It was jamming at the back and not opening all the way. I soon saw that the right-hand hinge was broken. We have a 7.5kg Simpson washing machine in which the computer died in our boneyard (where we store old washing machines for spare parts). I thought the lid was the same as the 9.5kg washing machine and would fit. So I thought it would be an easy repair. 86 Silicon Chip An internal photo of the Simpson-branded washing machine. I removed the four screws holding on the control panel, lifted up the control panel and moved it behind the machine, resting it on the tub. The lid hinges are held on with four screws, which I removed. I installed the replacement lid and replaced the control panel. However, when I tested the machine, it showed a lid error, indicating that the lid was still open. I checked the old lid and then realised that the lid switch was in a different location on the two machines; this machine had a tongue on the original lid that activated the lid switch and the tongue was also locked by a solenoid when the machine was in use. This did not exist on the 7.5kg machine. I decided that the best course of action would be to rewire this machine. I removed the lid switch from the 7.5kg machine and installed it in the 9.5kg machine. Next, I needed to locate the wires for the original lid switch. I could see that a wiring harness came from the front of the machine and emerged under the computer inside the control panel. After retrieving my multimeter, I started removing plugs, testing for the lid switch while opening and closing the lid. I could not find the wires for the lid switch on the computer, but I could see other wires going to the cycle control board. The plugs on the cycle control board were too small for me to be able to get the multimeter probes into. I decided to use my buzz-box, as it has clips on the leads and I could clip the leads onto two bent paperclips, which would fit in the plugs. I removed the plugs from the cycle control board and checked them while activating the lid switch by raising and lowering the lid. The lid switch wires were soon located – two thin green wires connected to the right-hand plug on the cycle control board. I cut the wires some distance from the plug, then cut the wires from the replacement lid switch to length. Australia's electronics magazine siliconchip.com.au I bared the ends of the wires, soldered them together, then covered the joints with heatshrink tubing. I plugged the plug back into the cycle control board and tested the washing machine to make sure that the lid switch was working correctly. My wife was happy to have the machine back in working order. She was also very happy to be rid of the lid lock, which was an annoyance. When the machine went out of balance and she needed to adjust the washing, she had to wait about 10 seconds for the lid to unlock before she could open it. It was more of a nuisance than a safety feature. It’s just common sense when lifting the lid to wait for the bowl siliconchip.com.au Australia's electronics magazine November 2026  87 to be stationary before putting your hands in to adjust the washing. It’s really handy keeping these old washing machines for spare parts. If I had to buy new parts, the cost would often exceed the value of the old machine. Bruce Pierson, Dundathu, Qld. K-Rain KRC9 irrigation controller installation challenges My daughter asked me to help her partner connect a new irrigation controller at her rental property. She said it would be easy because her partner had put the controller in place and run the cables to the required locations. There was one set of valves in the back garden and one set in the front garden. I asked what controller was being used so I could read up on the details before starting. The manual showed how to wire the valves and set them up. So, I was well prepared when I went to carry out the work. The controller was indeed attached to the wall with two five-core, 20m-long cables run to the location of the back garden valves. A third cable was run across the yard and a fourth down the side of the house to the location for the front garden valves. What I wasn’t told was that, as the cables were supplied as 20m long, the feed to the front garden had two joins to complete the circuit. The front solenoids would be 60m from the controller, but the installation manual indicated that the wiring should be 1mm diameter for runs over 50m. However, the cables that had been purchased and run only had 0.5mm diameter wires. The three solenoids at the front only needed four wires, so I decided to parallel two wires for the common to reduce the voltage drop along the cable and see if that worked. I joined the three cables leading to the front garden together, then shorted the black and white wires at the front garden end so I could identify which of the two cables at the controller end I needed to use for the front valves. The first cable I tested showed the short, so I marked it as the front feed. I then went back and shorted the remaining red, blue 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. and green wires together to prove the continuity of my joints. All tested OK. We then fitted the master solenoid and two others to a manifold and connected the water supply. I connected the solenoids to the cable running back to the controller. Now satisfied that all should work, I switched on the power and set the water to come on. Nothing happened, although the controller showed a display indicating that water should be running. I then noticed that the fuse in the controller had blown. Did we have a faulty solenoid or was the wiring faulty, despite my testing? I disconnected the solenoids and checked each one; they were all OK. I started my working life installing crossbar telephone exchanges, dealing with thousands of wires; surely I did not make a mistake with five wires! I then went back and double-checked my wiring joins; they all looked good. This was turning out to be very puzzling. I decided to look at the unused cable that was going to be for the back garden. I was amazed to see that the end away from the controller had all the insulation stripped from each wire and all five were shorted together! This was the answer; when I initially shorted the black and white in the front garden and tested it, I was seeing the back garden cable with all the conductors shorted together. Murphy’s Law was at it again. If I had tested the other cable first, all would have been good. I can only assume that all the conductors had been shorted together during testing after manufacturing. It was a simple matter to swap the cables at the controller and test again. To my relief, it all worked well that time. The back garden would have to wait for another day. John Western, Hillarys, WA. Faulty alarm controller The five wires shown inset had the insulation stripped from their ends and were shorted together. 88 Silicon Chip A few months ago, I received a phone call from a neighbor while we were out, informing us that our house alarm was going off, although there was no sign of entry. I hurried back and found the key panel was indicating a battery fault. The base unit is difficult to access, but when I managed to get to it, I found the battery was flat. Interestingly, it felt warm. It had only been replaced once in over 20 years, so I fitted another from a nearby battery retailer (12V 7.2Ah). The fault was cleared, and everything was OK – for about eight days. Until 1:30am, to be precise, when it went off again (sorry, neighbours). With bleary eyes, I checked the battery; it was also flat Australia's electronics magazine siliconchip.com.au Versatile Battery Checker This tool lets you check the condition of most common batteries, such as Li-ion, LiPo, SLA, 9V batteries, AA, AAA, C & D cells; the list goes on. It’s simple to use – just connect the battery to the terminals and its details will be displayed on the OLED readout. Versatile Battery Checker Complete Kit (SC7465, $65+post) Includes all parts and the case required to build the Versatile Battery Checker, except the optional programming header, batteries and glue See the article in the May 2025 issue for more details: siliconchip.au/Article/18121 and warm. I removed the battery and disconnected the AC, put the battery on a charger, and decided to attack it in the morning so that I could resume my beauty sleep (it didn’t work, unfortunately). The next morning, I examined the base unit. I connected the battery through an ammeter and recorded 300mA discharge – that seemed a bit high. I connected the mains input to check if it was charging, but it was still discharging at 50mA! I could see a bulge in the main filter cap, so the board had to come out. As you can see from the photo, there are lots of connectors. This alarm was installed by an electrician over 20 years ago when the house was being built. No doubt there is a map of where they all go somewhere, but I can’t find it, so I photographed it and also drew up a diagram of the wire colour codes and locations. As for the white commons, I marked each one with a different number of stripes using an indelible pen. The chance of replacing a board of that vintage was vanishingly small, and replacing a whole alarm system seemed horrifyingly expensive, so I thought I had better have a go at repairing it. Replacing the bulging capacitor was easy; it was 3300μF, but I replaced it with a 4700μF type I had lying around. It had the same pin spacing, but I knew there was more to it. The bridge rectifier was OK but the readings around the regulator seemed a bit strange. This was attached to the large heatsink on the right. Once removed, it measured 80W with either polarity between the input and output. This was an LM340T three-terminal regulator, which siliconchip.com.au is normally bulletproof. Perhaps trying to regulate a DC voltage with a large AC component proved too much, and it gave up the ghost. Luckily, I had one of them on hand as well. Everything has been good since – I wasn’t looking forward to trying to identify all the inputs if I had to replace it! SC Frank Murray, Downer, ACT. Since Frank Murray didn’t have a wiring diagram for his alarm controller, he took this picture and started marking the wire colour codes. Australia's electronics magazine November 2026  89