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SERVICEMAN'S LOG My father, the ultimate “serviceman” Once again we are into another year, and while most of us are focusing on getting back into the swing of things, for me, 2019 began with sadness. My dad Gary, the man who taught me so much, finally downed tools, passing away on December 20th, 2018. Ironically, it was the brain that gave him his skills and intellect that ultimately failed him, gradually robbing him of his talents. I’ve met many amazing and extremely clever people in my life and even some I would not hesitate to call a genius. My largely self-taught Dad stands tall among them. All of these people share common traits; an endless thirst for knowledge, a desire to learn anything new, a need to find out how something works and enviable skills with all manner of tools. I’m sure you know the type, and may even recognise some or all of these traits in yourself. As one would expect from a man who siliconchip.com.au lived for over eight decades, Dad had some intriguing and usually entertaining engineering and serviceman-related stories to tell. The problem was that I heard most of them from family members or friends; Dad was a man of few words and he didn’t waste any of them blowing his own trumpet. If pressed, he might sometimes confirm or modestly Australia’s electronics magazine Dave Thompson Items Covered This Month • • • The ultimate serviceman Dishwasher repair Tractor display module repair *Dave Thompson runs PC Anytime in Christchurch, NZ. Website: www.pcanytime.co.nz Email: dave<at>pcanytime.co.nz disclaim some of the details, assigning positive outcomes to ‘luck’ or somebody else who was involved, but I’d like to believe the stories were all true. I could fill a book with these anecdotes, and might just do that one day. One example: it wasn’t until I made my first electric guitar at 18 that Dad informed me that he too had made one in his youth. Dad didn’t have a musi- March 2019  57 cal bone in his body (some may argue that I don’t either!) but that didn’t stop him making his own instrument. While I utilised a lot of donated or store-bought hardware, he fabricated almost everything on his guitar – the bridge, pickups and even the machine heads! The desire to do this most likely came more from a position of not having a lot of money or a source of suitable components than anything else. But ANZACs in his peer group have a well-deserved reputation for “doing it themselves”. While Dad never had a full-time job as an actual serviceman, he’d built a reputation as a person who could repair or fabricate just about anything. So he ended up doing a lot of repair and custom work. Someone once gave him a broken Bakelite and brass steering-wheel bezel from a vintage car to restore but as it was too far gone, he hand-fabricated a whole new one from period materials. Word slowly got around the global vintage car community (this was the 70s) and soon he was making bespoke car 58 Silicon Chip parts for enthusiasts all over the world. Nowadays, people can get whatever they need made in China or India, or maybe even 3D print it, but back then the only option (other than finding an original part) was to get an engineer to make one for you. While I don’t think he did a huge amount of this particular work, this is typical of how he could easily shift gears and take advantage of opportunities that came his way. Some clever inventions While I was around for a lot of his working life, I heard anecdotes at his funeral about his younger days that were news to me. I would have dearly loved to have discussed them with him to get more details. I knew he’d built several electric vehicles in the late 60s for a business ‘up north’, and also built an electric cart and trailer that ferried tourists around the Christchurch Botanical Gardens for decades. But where he got the plans or even the parts for these vehicles, I have no idea. Australia’s electronics magazine I recall being very proud when as a lad I saw him being interviewed by a reporter about these EVs on the family’s first black-and-white television (that Dad had also made). I was also aware he designed and made height-adjustable rotary clotheslines for both his mother and my mother using hydraulic rams; at the turn of a water tap, the ladies could raise the washing line to almost double its normal height, catching more sun and breeze in an increasingly fenced-in and crowded suburbia. As small children we would take turns hanging on and riding up and down these washing-lines, treating them as our own personal fairground rides (much to the adults’ consternation!). At the service, I also heard about a colossal quilting machine Dad built from scratch and installed in a textiles factory some time in the late 50s or early 60s, all from a single photograph taken by the factory owner of a similar contraption operating in America. This sewing-machine-on-steroids followed configurable tracks built into the factory floor to create patterns in the material and was apparently used well into the 80s. Yet another custom machine mentioned was one I had better memories of; designed and built in the late 60s, it made both solid and hollow fishing rod blanks from great reels of fibreglass strands. The solid blanks this machine produced would later be repurposed for CB-radio whip antennas, when Dad and another guy ran a business designing, assembling and installing their own CB radio (the Telstat Minicom) during the mid-70s CB boom. I can actually remember this machine and the reels of glass threads taking up half the space of an old gutted house Dad rented at the time. I mainly remember the heat and smell from the machine; to this day, the smell of fibreglass takes me back to that old house. Any of these ideas, with the right backing, could make someone a fortune. But for Dad it was more the challenge of coming up with an idea, making it a reality and then moving on to the next project. Creating anything similar today, even with all the plans, knowledge and experience on-tap via the internet would be tough going; back then, all Dad had was his hands, his imagination and a siliconchip.com.au well-equipped workshop. One must respect a man with such abilities. A flair for repair Another story told at his funeral, which has since been corroborated by one of the parties involved (who also happens to be a from-day-one Silicon Chip reader), occurred way before my time and involved an innovative impromptu repair, something that Dad was very good at, even as a younger man. The story goes that Dad had recently turned 15 and gained his driver’s licence. He was hooning around Christchurch in an old Whippet sedan with his younger brother Roger when the car lost power and a knocking noise was heard coming from the motor. Dad apparently had a good idea of what it was likely to be and proceeded to climb under the car and drop the sump from the engine right there on the roadside. For as long as I could remember, and until only recently, Dad always carried a four-inch Crescent shifter around in his trouser pocket. Perhaps he had one with him even then. He visually confirmed they had run a big-end bearing, which for the majority of us would be the end of the line. Not one to be beaten by a simple bearing failure, Dad asked for his brother’s brand-new leather belt and to Roger’s horror, he proceeded to cut it up, fashioning a new makeshift bearing from it. He then bolted everything back together and replaced the oil, which he had kept. Off they went on their merry way and the engine was said to be still going well when they sold the car. I wonder if they mentioned the leather bearing to the new owner... In one of life’s strange coincidences, one of Dad’s school-mates ended up being my foreman at the airline I worked at, and he would occasionally regale me with stories about youthful scrapes he and Dad got into. He recalled that one fine day they were out riding their prized motorbikes in the countryside when his bike suddenly clattered to a stop in a cloud of smoke. Something was obviously wrong with the engine, and as they were a fair way out of town, this was potentially very inconvenient. Again, not wanting to be thwarted by a measly motorbike engine failure, and using the toolkit that came with siliconchip.com.au his own motorbike, Dad stripped the dead motor down by the side of the road. He soon had it reassembled and running and they both made it home. His mate couldn’t recall precisely what was wrong with the motor, and when I asked Dad about it, he said he’d found it had a blocked oil line and put it down to a fluke that he found the problem and managed to get it going again. Harking back to my younger days It’s no wonder that I grew up with the confidence that no matter what predicament we as a family got into, Dad would find a way to get us out of it. When I was younger, I always drove cheaper cars, preferring to spend my meagre disposable income on electronic components, model planes and tools. Of course, this is a false economy, as cheap cars tend to break down a lot. I was always adding bits and pieces to these cars, usually from projects out of the likes of Everyday Electronics, Practical Electronics and Electronics Australia (obviously I spent a lot of money on magazines as well!). The usual mods would be to add a capacitor-discharge ignition, wiper delay units, hazard flashers, a car alarm and any other easy-to-build widget or gadget I could afford to install. This taught me a lot about systems and the importance of good construction. Dad taught me to solder when I was old enough to know which end of the soldering iron to hold onto without getting hurt, so this was never an issue, but I did have a lot to learn about installations. Dad to the rescue In one older (and frankly rubbish) car I owned, I’d installed a stalkmounted high/low beam switch. This car usually had a floor-mounted dip switch and as that switch was failing, I decided to mount one up by the steering wheel, just like all the more modern cars of the time. Since the advent of sourcing wiring diagrams for cars with a simple internet search was about 30 years away, I busied myself instead by ‘ringing out’ the existing wiring with Dad’s multimeter. Cars back then are not like cars today, with massively-complicated wiring looms, computers and cosmetic panelling getting in the way, but at the time it seemed complex to me. I finally isolated the wiring for the switch and the lights and ran a couple of wires in parallel from the floor switch to the new toggle switch I’d mounted to the steering column using a hose clamp. When I’d wired it all in, the new switch worked perfectly and I was well pleased with myself. However, a few nights later I was out and about and when I switched the lights on, the fuse blew and I had no headlights. As I had no spare fuses, I walked to a nearby telephone box (remember them?) and called Dad. He jumped in his car and came out to where I’d parked up and brought a torch and some spare fuses with him. After installing one, we tried the lights but blew the fuse again. Dad then used the torch to have a quick look at the work I’d done and soon found the culprit; the switch had slowly moved under the metal clamp and this had bridged the terminals to ground. He removed the clamp, allowing the switch to dangle and replaced the fuse. This time everything worked, and I won’t forget the look I got as he explained that taking the time to mount components properly and insulating any bare terminals is always a good idea! One afternoon and in yet another ageing car, I had the misfortune of the engine cutting out in the middle of a large roundabout. The passenger and I pushed the car into the grass centre of the roundabout and after a quick look under the hood to determine the cause, I concluded I had no spark. The CDI ignition that I’d proudly built and installed a month back must have failed. Servicing Stories Wanted Do you have any good servicing stories that you would like to share in The Serviceman column? If so, why not send those stories in to us? 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 March 2019  59 Once again I made the call of shame to Dad. He soon turned up in his car and asked why, if I suspected the new ignition, I hadn’t simply bypassed it and re-wired the old system back in, which on his advice I’d left intact in case I wanted to restore the car to its original state. I had to sheepishly admit – in front of my friend no less – that I didn’t really know how to do that, having not taken much notice of how it was before I rushed in and installed the other one. Once again I got the look, and within a few minutes, he had swapped everything back to factory and got the engine running. He followed me home just in case, but it was another lesson learned. Bitten by the flying bug His lifelong love of all things aircraft and engineering meant he was a natural aeromodeller. My brother and I also got the bug, and Dad was generous with his skills, time and money to ensure we always had the best gear available, even though we sometimes tried our best to ruin it by recklessly flying our models way too close to – if not actually into – the ground. When I got the crazy idea to build a pulse-jet powered model, rather than talk me out of it, Dad made the gear I’d need to support it, like a die to massproduce the thin, stainless-steel petal valves I would be burning out on a regular basis, as well as an electronic ignition system and a portable, compressed-air starter. Lighting up the garage at night as we test-ran that extremely loud and dangerous pulse jet clamped to his band-saw table is something I won’t forget in a hurry! Possibly his crowning model-engineering achievements were the largescale, chainsaw-motor-powered P51 Mustang model he built and flew at air shows and the gas-turbine engines he produced in the 90s. While you can buy a commercial turbine today (at considerable expense), he built his engines himself. Initially utilising repurposed housings, ceramic bearings and impellers from car turbochargers (to handle the 100,000 RPM-plus shaft speeds), Dad experimented extensively with different materials, fabricating everything else he needed. His engines and models broke speed records and thrilled spectators at air 60 Silicon Chip shows all over the country and he really pushed the limits of what a skilled fabricator in a home workshop could achieve. All the stories and his achievements inspired me to become an aircraft engineer and electronics enthusiast. Through it all, Dad was always supportive, constantly interested and free with his time, his skills and his sage advice. I shall sorely miss him. Thanks, Dad; job well done. Dishwasher repair J. F., of Ivanhoe, Vic, discovered that some repairs are not difficult, just tedious. He had to fix a basic dishwasher which had wiring that wasn’t quite up to the job... Dave Thompson’s dishwasher repair story in the August 2018 issue reminds me that several years ago I virtually rebuilt the wiring on a Hoover dishwasher. It was fitted with a mechanical rotary timer actuator located on the front of the door with bundles of leads running down the inside of the door and turning 90° to go under the base to each of the motors, solenoids etc. The problem was each time the door was opened, the wiring bundle (with over thirty separate wires) was flexed where it came out of the door into the underside of the dishwasher. The original cables had 75°C rated insulation and a dishwasher can get hotter than that, so over time the plasticiser evaporated and the insulation became rigid. Eventually, the wires broke and went open circuit. At the time, I worked for a large manufacturer and the friendly maintenance electricians suggested cabling with insulation rated for 105°C (this came in a variety of colours), so it was “just” a matter of replacing each cable in turn with the higher rated ones. I sat the dishwasher on a set of carpenter’s stools to access the underside components; I was used to lying under motor cars, so this didn’t seem unnatural to me. It was a laborious job but it fixed the problem and the unit lasted for many years until we renovated our kitchen. Tractor measurement display module repair It’s good to keep your brain active even after you retire. R. M. may have given up his technician job and moved Australia’s electronics magazine to the country but he still enjoys taking on some of the more unusual servicing jobs. Here is the story of a recent repair that involved some techniques well outside his comfort zone... It has been nearly twelve years since I retired from my University Electronics Technician role of forty years. My wife and I moved to a beautiful little town on the south coast of Western Australia, to a small farm. When people found what I used to do, they’d get a shifty look in the eye and say, “So you know about electronic stuff eh? I’ve got this (electronic, electrical, electro-mechanical, mechanical, not even remotely electronic) thing that doesn’t work. D’ya think you could have a quick look at it?” Of course I do. And sometimes even manage to effect some sort of repair. It’s a good way to keep the mental gears spinning. Recently my friend Wayne, a fellow volunteer firefighter, asked me whether I could take a look at his tractor’s faulty dashboard. A tractor? Who could resist! It was a fairly new John Deere 5100R, a hulking great green beast. The display module behind the steering wheel has a row of coloured lights, two large analog dials (for road speed and engine/power take-off RPM), two smaller analog dials (fuel level and engine temperature) and a small LCD screen. It was this LCD that was having problems. Sometimes some parts of the display would disappear and sometimes, all of it would be gone. This display shows a lot of obscure but useful metrics; stuff that Wayne often relies upon when doing contract spraying or seeding. The local John Deere agent said that they don’t repair these display modules and a new one would cost around $2000 including GST and freight. Well, Wayne reckoned that was too expensive so he asked me whether I could fix it. My first guess was that the LCD was connected with one of those conductive elastomer strips you see on DMM displays. Lots of vibration could have loosened it. I asked Wayne to bring the module around to my place and I then removed a few screws so I could pop open the case, giving me a better view of the LCD. It was attached to a wide, flat grey ribbon cable that snaked down between two PCBs. Getting a look at siliconchip.com.au where it connected to the boards required more disassembly that I was willing to attempt at the time. A quick Google search for “John Deere 5100R dashboard repair” brought up a lot of mostly useless hits, but there was a video of cheerful German techies unsoldering and replacing the display using solder paste. I had never done that before but I was prepared to give it a go. A bit more Googling came up with a supplier for the replacement part, in Spain of all places; I passed this information on to Wayne. Several weeks later, he was back with the dashboard display and a cardboard box containing the new LCD. We agreed that I would “give it my best shot” but there was no guarantee that this would work. In the worst case, he’d be down $70 (the cost of the replacement LCD) and my reputation as a fix-it guru would be in tatters. Faced with that old demon, fear of failure, it was a few days before I could work up enough courage to start the job. Finally game to give it a go, I opened the case again. The next step was to remove the pointers on the four dials so that the display panel could come out. The dials were driven by rotary actuators mounted on the back of the PCB, directly behind the display panel. The two bigger pointers had a black disc covering the central boss, so I removed one of the discs. I then used a pair of curved tweezers like a tiny crowbar between the panel and pointer, exerting a bit of upwards pressure on the pointer and it quickly popped off. siliconchip.com.au I repeated this technique to remove the other three pointers. I could then remove the panel and pull the two PCBs apart, which were simply joined by two multi-pin connectors that pulled apart easily. This finally gave me access to the PCB where the LCD ribbon cable attached. The board was well made with a scattering of SMDs interconnected with frighteningly fine tracks. The whole lot was covered with a hard clear varnish as thick and shiny as the sugar glaze on a toffee apple. Except (happily) for the area where the ribbon cable was attached. And yes, it was firmly soldered to the board (or so I thought). I had to remove the ribbon so that I could attach the new display. I gingerly touched the tip of my iron to the top of the first contact between ribbon and pad while being ready with tweezers to lift the ribbon up. The reaction was rapid and alarming – the plastic ribbon instantly melted and squirmed away from the hot iron! All I could do was to proceed with melting off this mucky ribbon. Having done so, it was time to examine the damage. The end of the ribbon was a sorry sight, all twisted and gnarly. But the solder pads on the PCB were fine bright gold plated. There was no sign of any solder! The tracks, now that I could see them, were not metal but more like some sort of printed conductor. It seems that the ribbon cable had simply been glued in place. That’s an easy way to guarantee failure! It’s interesting to note that the version the techs in the YouTube video were working on was definitely soldered. I removed the remaining plastic residue using some careful Australia’s electronics magazine scraping with a craft knife and a bit of contact cleaner. I then polished the pads up with a touch of isopropyl alcohol and a cotton bud. I was now ready for the final act: soldering on the new LCD and ribbon. I checked it carefully and was infinitely pleased to see that it was indeed a proper solderable type. But how would I hold it in place, accurately aligned with the pads while I applied heat? There were a couple of components annoyingly placed so as to not allow the ribbon to lay flat. I checked the video of the happy German techs; they had an elaborate special jig to hold everything sweet. Lacking that, I decided instead to use double-sided tape to hold it in place. I found that a thin strip of tape just below the pads held the ribbon just right. I had previously used the syringe applicator to apply 36 little blobs of solder paste on the 36 gold pads. Now, all that I needed to do was to heat the back of the ribbon, to melt the paste. After all that had gone before, the job that I had spent all this time working towards turned out to be quite anti-climatic. The paste melted immediately. Surface tension sucked the resultant liquid solder onto the pads. I ran the iron back and forth a few times to ensure that there were no solder bridges and the job was done! With great relief, I put everything back together. I carefully aligned the pointers on zero while the actuators were fully counter-clockwise. When the final screws were in place and the case clicked together, I allowed myself to breathe again. Then I phoned Wayne with the possibly good news that I’d like to come over and see if the thing would now work. He agreed cheerfully and within half an hour the module was back in place and plugged in. Moment of truth – Wayne started the engine and over the loud diesel throb I heard him exclaim, “Hey look at that! The clock works. I’d forgotten there was a clock!” We ran through all the parameters and everything worked perfectly. Wayne was thrilled. I was immensely relieved and delighted that I’d helped a mate. And I had kept my reputation intact. “Hey, Roy,” said Wayne, “I’ve got this mate with a MIG welder that stopped working. D’ya think you could…” SC March 2019  61